background-color for tiptap 2

back-color.ts

import { Extension } from "@tiptap/core";
import "@tiptap/extension-text-style";

export type ColorOptions = {
  types: string[];
};

declare module "@tiptap/core" {
  interface Commands<ReturnType> {
    backColor: {
      /**
       * Set the text color
       */
      setBackColor: (color: string) => ReturnType;
      /**
       * Unset the text color
       */
      unsetBackColor: () => ReturnType;
    };
  }
}

export const BackColor = Extension.create<ColorOptions>({
  name: "backColor",

  addOptions() {
    return {
      types: ["textStyle"],
    };
  },

  addGlobalAttributes() {
    return [
      {
        types: this.options.types,
        attributes: {
          backgroundColor: {
            default: null,
            parseHTML: (element) =>
              element.style.backgroundColor.replace(/['"]+/g, ""),
            renderHTML: (attributes) => {
              if (!attributes.backgroundColor) {
                return {};
              }

              return {
                style: `background-color: ${attributes.backgroundColor}`,
              };
            },
          },
        },
      },
    ];
  },

  addCommands() {
    return {
      setBackColor:
        (color) =>
        ({ chain }) => {
          return chain().setMark("textStyle", { backgroundColor: color }).run();
        },
      unsetBackColor:
        () =>
        ({ chain }) => {
          return chain()
            .setMark("textStyle", { backgroundColor: null })
            .removeEmptyTextStyle()
            .run();
        },
    };
  },
});

This is the background color I implemented like color, hope it is useful :))

import { Extension } from '@tiptap/core'

export type BackgroundColorOptions = {
  /**
   * The types where the color can be applied
   * @default ['textStyle']
   * @example ['heading', 'paragraph']
   */
  types: string[]
}

declare module '@tiptap/core' {
  interface Commands<ReturnType> {
    backgroundColor: {
      /**
       * Set the background color
       */
      setBackgroundColor: (color: string) => ReturnType
      /**
       * Unset the background color
       */
      unsetBackgroundColor: () => ReturnType
    }
  }
}

export const BackgroundColor = Extension.create<BackgroundColorOptions>({
  name: 'backgroundColor',

  addOptions() {
    return {
      types: ['textStyle']
    }
  },

  addGlobalAttributes() {
    return [
      {
        types: this.options.types,
        attributes: {
          backgroundColor: {
            default: null,
            parseHTML: (element) => element.style.backgroundColor?.replace(/['"]+/g, ''),
            renderHTML: (attributes) => {
              if (!attributes.backgroundColor) {
                return {}
              }

              return {
                style: `background-color: ${attributes.backgroundColor}`
              }
            }
          }
        }
      }
    ]
  },

  addCommands() {
    return {
      setBackgroundColor:
        (color) =>
        ({ chain }) => {
          return chain().setMark('textStyle', { backgroundColor: color }).run()
        },
      unsetBackgroundColor:
        () =>
        ({ chain }) => {
          return chain()
            .setMark('textStyle', { backgroundColor: null })
            .removeEmptyTextStyle()
            .run()
        }
    }
  }
})

Very good code! But be aware that need to import @tiptap/extension-text-style, otherwise you will get an error removeEmptyTextStyle not found!