invert!

frontend/public/locales/en-GB/translation.json

@@ -621,6 +621,10 @@
       "title": "Replace & Invert Colour",
       "desc": "Replace or invert colours in PDF documents"
     },
+    "replaceColor": {
+      "title": "Replace & Invert Colour",
+      "desc": "Replace or invert colours in PDF documents"
+    },
     "devApi": {
       "tags": "API,development,documentation",
       "title": "API",
@@ -2509,7 +2513,7 @@
       "3": "Custom(Customised colours)",
       "4": "Full-Invert(Invert all colours)",
       "5": "High contrast colour options",
-      "6": "white text on black background",
+      "6": "White text on black background",
       "7": "Black text on white background",
       "8": "Yellow text on black background",
       "9": "Green text on black background",
@@ -2518,6 +2522,47 @@
     },
     "submit": "Replace"
   },
+  "replaceColor": {
+    "labels": {
+      "settings": "Settings",
+      "colourOperation": "Colour operation"
+    },
+    "options": {
+      "highContrast": "High contrast",
+      "invertAll": "Invert all colours",
+      "custom": "Custom"
+    },
+    "tooltip": {
+      "header": {
+        "title": "Replace & Invert Colour Settings Overview"
+      },
+      "description": {
+        "title": "Description",
+        "text": "Transform PDF colours to improve readability and accessibility. Choose from high contrast presets, invert all colours, or create custom colour schemes."
+      },
+      "highContrast": {
+        "title": "High Contrast",
+        "text": "Apply predefined high contrast colour combinations designed for better readability and accessibility compliance.",
+        "bullet1": "White text on black background - Classic dark mode",
+        "bullet2": "Black text on white background - Standard high contrast",
+        "bullet3": "Yellow text on black background - High visibility option",
+        "bullet4": "Green text on black background - Alternative high contrast"
+      },
+      "invertAll": {
+        "title": "Invert All Colours",
+        "text": "Completely invert all colours in the PDF, creating a negative-like effect. Useful for creating dark mode versions of documents or reducing eye strain in low-light conditions."
+      },
+      "custom": {
+        "title": "Custom Colours",
+        "text": "Define your own text and background colours using the colour pickers. Perfect for creating branded documents or specific accessibility requirements.",
+        "bullet1": "Text colour - Choose the colour for text elements",
+        "bullet2": "Background colour - Set the background colour for the document"
+      }
+    },
+    "error": {
+      "failed": "An error occurred while processing the colour replacement."
+    }
+  },
   "replaceColorPdf": {
     "tags": "Replace Colour,Page operations,Back end,server side"
   },

frontend/src/components/tools/replaceColor/ReplaceColorSettings.tsx

@@ -0,0 +1,108 @@
+import React from "react";
+import { Stack, Text, Select, ColorInput } from "@mantine/core";
+import { useTranslation } from "react-i18next";
+import { ReplaceColorParameters } from "../../../hooks/tools/replaceColor/useReplaceColorParameters";
+
+interface ReplaceColorSettingsProps {
+  parameters: ReplaceColorParameters;
+  onParameterChange: <K extends keyof ReplaceColorParameters>(key: K, value: ReplaceColorParameters[K]) => void;
+  disabled?: boolean;
+}
+
+const ReplaceColorSettings = ({ parameters, onParameterChange, disabled = false }: ReplaceColorSettingsProps) => {
+  const { t } = useTranslation();
+
+  const replaceAndInvertOptions = [
+    {
+      value: 'HIGH_CONTRAST_COLOR',
+      label: t('replaceColor.options.highContrast', 'High contrast')
+    },
+    {
+      value: 'FULL_INVERSION',
+      label: t('replaceColor.options.invertAll', 'Invert all colours')
+    },
+    {
+      value: 'CUSTOM_COLOR',
+      label: t('replaceColor.options.custom', 'Custom')
+    }
+  ];
+
+  const highContrastOptions = [
+    {
+      value: 'WHITE_TEXT_ON_BLACK',
+      label: t('replace-color.selectText.6', 'White text on black background')
+    },
+    {
+      value: 'BLACK_TEXT_ON_WHITE',
+      label: t('replace-color.selectText.7', 'Black text on white background')
+    },
+    {
+      value: 'YELLOW_TEXT_ON_BLACK',
+      label: t('replace-color.selectText.8', 'Yellow text on black background')
+    },
+    {
+      value: 'GREEN_TEXT_ON_BLACK',
+      label: t('replace-color.selectText.9', 'Green text on black background')
+    }
+  ];
+
+  return (
+    <Stack gap="md">
+      <Stack gap="xs">
+        <Text size="sm" fw={500}>
+          {t('replaceColor.labels.colourOperation', 'Colour operation')}
+        </Text>
+        <Select
+          value={parameters.replaceAndInvertOption}
+          onChange={(value) => value && onParameterChange('replaceAndInvertOption', value as ReplaceColorParameters['replaceAndInvertOption'])}
+          data={replaceAndInvertOptions}
+          disabled={disabled}
+        />
+      </Stack>
+
+      {parameters.replaceAndInvertOption === 'HIGH_CONTRAST_COLOR' && (
+        <Stack gap="xs">
+          <Text size="sm" fw={500}>
+            {t('replace-color.selectText.5', 'High contrast color options')}
+          </Text>
+          <Select
+            value={parameters.highContrastColorCombination}
+            onChange={(value) => value && onParameterChange('highContrastColorCombination', value as ReplaceColorParameters['highContrastColorCombination'])}
+            data={highContrastOptions}
+            disabled={disabled}
+          />
+        </Stack>
+      )}
+
+      {parameters.replaceAndInvertOption === 'CUSTOM_COLOR' && (
+        <>
+          <Stack gap="xs">
+            <Text size="sm" fw={500}>
+              {t('replace-color.selectText.10', 'Choose text Color')}
+            </Text>
+            <ColorInput
+              value={parameters.textColor}
+              onChange={(value) => onParameterChange('textColor', value)}
+              format="hex"
+              disabled={disabled}
+            />
+          </Stack>
+
+          <Stack gap="xs">
+            <Text size="sm" fw={500}>
+              {t('replace-color.selectText.11', 'Choose background Color')}
+            </Text>
+            <ColorInput
+              value={parameters.backGroundColor}
+              onChange={(value) => onParameterChange('backGroundColor', value)}
+              format="hex"
+              disabled={disabled}
+            />
+          </Stack>
+        </>
+      )}
+    </Stack>
+  );
+};
+
+export default ReplaceColorSettings;

frontend/src/components/tooltips/useReplaceColorTips.ts

@@ -0,0 +1,40 @@
+import { useTranslation } from 'react-i18next';
+import { TooltipContent } from '../../types/tips';
+
+export const useReplaceColorTips = (): TooltipContent => {
+  const { t } = useTranslation();
+
+  return {
+    header: {
+      title: t("replaceColor.tooltip.header.title", "Replace & Invert Colour Settings Overview")
+    },
+    tips: [
+      {
+        title: t("replaceColor.tooltip.description.title", "Description"),
+        description: t("replaceColor.tooltip.description.text", "Transform PDF colours to improve readability and accessibility. Choose from high contrast presets, invert all colours, or create custom colour schemes.")
+      },
+      {
+        title: t("replaceColor.tooltip.highContrast.title", "High Contrast"),
+        description: t("replaceColor.tooltip.highContrast.text", "Apply predefined high contrast colour combinations designed for better readability and accessibility compliance."),
+        bullets: [
+          t("replaceColor.tooltip.highContrast.bullet1", "White text on black background - Classic dark mode"),
+          t("replaceColor.tooltip.highContrast.bullet2", "Black text on white background - Standard high contrast"),
+          t("replaceColor.tooltip.highContrast.bullet3", "Yellow text on black background - High visibility option"),
+          t("replaceColor.tooltip.highContrast.bullet4", "Green text on black background - Alternative high contrast")
+        ]
+      },
+      {
+        title: t("replaceColor.tooltip.invertAll.title", "Invert All Colours"),
+        description: t("replaceColor.tooltip.invertAll.text", "Completely invert all colours in the PDF, creating a negative-like effect. Useful for creating dark mode versions of documents or reducing eye strain in low-light conditions.")
+      },
+      {
+        title: t("replaceColor.tooltip.custom.title", "Custom Colours"),
+        description: t("replaceColor.tooltip.custom.text", "Define your own text and background colours using the colour pickers. Perfect for creating branded documents or specific accessibility requirements."),
+        bullets: [
+          t("replaceColor.tooltip.custom.bullet1", "Text colour - Choose the colour for text elements"),
+          t("replaceColor.tooltip.custom.bullet2", "Background colour - Set the background colour for the document")
+        ]
+      }
+    ]
+  };
+};

frontend/src/data/useTranslatedToolRegistry.tsx

@@ -50,6 +50,7 @@ import { redactOperationConfig } from "../hooks/tools/redact/useRedactOperation"
 import { rotateOperationConfig } from "../hooks/tools/rotate/useRotateOperation";
 import { changeMetadataOperationConfig } from "../hooks/tools/changeMetadata/useChangeMetadataOperation";
 import { cropOperationConfig } from "../hooks/tools/crop/useCropOperation";
+import { replaceColorOperationConfig } from "../hooks/tools/replaceColor/useReplaceColorOperation";
 import CompressSettings from "../components/tools/compress/CompressSettings";
 import SplitSettings from "../components/tools/split/SplitSettings";
 import AddPasswordSettings from "../components/tools/addPassword/AddPasswordSettings";
@@ -68,12 +69,14 @@ import RedactSingleStepSettings from "../components/tools/redact/RedactSingleSte
 import RotateSettings from "../components/tools/rotate/RotateSettings";
 import Redact from "../tools/Redact";
 import AdjustPageScale from "../tools/AdjustPageScale";
+import ReplaceColor from "../tools/ReplaceColor";
 import { ToolId } from "../types/toolId";
 import MergeSettings from '../components/tools/merge/MergeSettings';
 import { adjustPageScaleOperationConfig } from "../hooks/tools/adjustPageScale/useAdjustPageScaleOperation";
 import AdjustPageScaleSettings from "../components/tools/adjustPageScale/AdjustPageScaleSettings";
 import ChangeMetadataSingleStep from "../components/tools/changeMetadata/ChangeMetadataSingleStep";
 import CropSettings from "../components/tools/crop/CropSettings";
+import ReplaceColorSettings from "../components/tools/replaceColor/ReplaceColorSettings";
 
 const showPlaceholderTools = true; // Show all tools; grey out unavailable ones in UI
 
@@ -642,10 +645,14 @@ export function useFlatToolRegistry(): ToolRegistry {
       replaceColorPdf: {
         icon: <LocalIcon icon="format-color-fill-rounded" width="1.5rem" height="1.5rem" />,
         name: t("home.replaceColorPdf.title", "Replace & Invert Color"),
-        component: null,
+        component: ReplaceColor,
         description: t("home.replaceColorPdf.desc", "Replace or invert colors in PDF documents"),
         categoryId: ToolCategoryId.ADVANCED_TOOLS,
         subcategoryId: SubcategoryId.ADVANCED_FORMATTING,
+        maxFiles: -1,
+        endpoints: ["replace-invert-pdf"],
+        operationConfig: replaceColorOperationConfig,
+        settingsComponent: ReplaceColorSettings,
         synonyms: getSynonyms(t, "replaceColorPdf"),
       },
       addImage: {

frontend/src/hooks/tools/replaceColor/useReplaceColorOperation.ts

@@ -0,0 +1,38 @@
+import { useTranslation } from 'react-i18next';
+import { ToolType, useToolOperation } from '../shared/useToolOperation';
+import { createStandardErrorHandler } from '../../../utils/toolErrorHandler';
+import { ReplaceColorParameters, defaultParameters } from './useReplaceColorParameters';
+
+export const buildReplaceColorFormData = (parameters: ReplaceColorParameters, file: File): FormData => {
+  const formData = new FormData();
+  formData.append('fileInput', file);
+
+  formData.append('replaceAndInvertOption', parameters.replaceAndInvertOption);
+
+  if (parameters.replaceAndInvertOption === 'HIGH_CONTRAST_COLOR') {
+    formData.append('highContrastColorCombination', parameters.highContrastColorCombination);
+  } else if (parameters.replaceAndInvertOption === 'CUSTOM_COLOR') {
+    formData.append('textColor', parameters.textColor);
+    formData.append('backGroundColor', parameters.backGroundColor);
+  }
+
+  return formData;
+};
+
+export const replaceColorOperationConfig = {
+  toolType: ToolType.singleFile,
+  buildFormData: buildReplaceColorFormData,
+  operationType: 'replaceColor',
+  endpoint: '/api/v1/misc/replace-invert-pdf',
+  multiFileEndpoint: false,
+  defaultParameters,
+} as const;
+
+export const useReplaceColorOperation = () => {
+  const { t } = useTranslation();
+
+  return useToolOperation<ReplaceColorParameters>({
+    ...replaceColorOperationConfig,
+    getErrorMessage: createStandardErrorHandler(t('replaceColor.error.failed', 'An error occurred while processing the color replacement.'))
+  });
+};

frontend/src/hooks/tools/replaceColor/useReplaceColorParameters.ts

@@ -0,0 +1,29 @@
+import { BaseParameters } from '../../../types/parameters';
+import { useBaseParameters, BaseParametersHook } from '../shared/useBaseParameters';
+
+export interface ReplaceColorParameters extends BaseParameters {
+  replaceAndInvertOption: 'HIGH_CONTRAST_COLOR' | 'CUSTOM_COLOR' | 'FULL_INVERSION';
+  highContrastColorCombination: 'WHITE_TEXT_ON_BLACK' | 'BLACK_TEXT_ON_WHITE' | 'YELLOW_TEXT_ON_BLACK' | 'GREEN_TEXT_ON_BLACK';
+  textColor: string;
+  backGroundColor: string;
+}
+
+export const defaultParameters: ReplaceColorParameters = {
+  replaceAndInvertOption: 'HIGH_CONTRAST_COLOR',
+  highContrastColorCombination: 'WHITE_TEXT_ON_BLACK',
+  textColor: '#000000',
+  backGroundColor: '#ffffff',
+};
+
+export type ReplaceColorParametersHook = BaseParametersHook<ReplaceColorParameters>;
+
+export const useReplaceColorParameters = (): ReplaceColorParametersHook => {
+  return useBaseParameters({
+    defaultParameters,
+    endpointName: 'replace-invert-pdf',
+    validateFn: (params) => {
+      // All parameters are always valid as they have defaults
+      return true;
+    },
+  });
+};

frontend/src/tools/ReplaceColor.tsx

@@ -0,0 +1,58 @@
+import { useTranslation } from "react-i18next";
+import { createToolFlow } from "../components/tools/shared/createToolFlow";
+import ReplaceColorSettings from "../components/tools/replaceColor/ReplaceColorSettings";
+import { useReplaceColorParameters } from "../hooks/tools/replaceColor/useReplaceColorParameters";
+import { useReplaceColorOperation } from "../hooks/tools/replaceColor/useReplaceColorOperation";
+import { useBaseTool } from "../hooks/tools/shared/useBaseTool";
+import { BaseToolProps, ToolComponent } from "../types/tool";
+import { useReplaceColorTips } from "../components/tooltips/useReplaceColorTips";
+
+const ReplaceColor = (props: BaseToolProps) => {
+  const { t } = useTranslation();
+  const replaceColorTips = useReplaceColorTips();
+
+  const base = useBaseTool(
+    'replaceColor',
+    useReplaceColorParameters,
+    useReplaceColorOperation,
+    props
+  );
+
+  return createToolFlow({
+    files: {
+      selectedFiles: base.selectedFiles,
+      isCollapsed: base.hasResults,
+    },
+    steps: [
+      {
+        title: t("replaceColor.labels.settings", "Settings"),
+        isCollapsed: base.settingsCollapsed,
+        onCollapsedClick: base.settingsCollapsed ? base.handleSettingsReset : undefined,
+        tooltip: replaceColorTips,
+        content: (
+          <ReplaceColorSettings
+            parameters={base.params.parameters}
+            onParameterChange={base.params.updateParameter}
+            disabled={base.endpointLoading}
+          />
+        ),
+      },
+    ],
+    executeButton: {
+      text: t("replace-color.submit", "Replace"),
+      isVisible: !base.hasResults,
+      loadingText: t("loading"),
+      onClick: base.handleExecute,
+      disabled: !base.params.validateParameters() || !base.hasFiles || !base.endpointEnabled,
+    },
+    review: {
+      isVisible: base.hasResults,
+      operation: base.operation,
+      title: t("replace-color.title", "Replace-Invert-Color"),
+      onFileClick: base.handleThumbnailClick,
+      onUndo: base.handleUndo,
+    },
+  });
+};
+
+export default ReplaceColor as ToolComponent;