Highlight text: Color of highlighted text is not preserved when setting text color in the text block

[fluiddot]

Description

On a text block (e.g. Paragraph block) setting a text color changes the color displayed for all its content, including the parts that are highlighted with a different color. This behavior differs from the web version of the editor.

Step-by-step reproduction instructions

1. Add a Paragraph block.
2. Type some text.
3. Select a word.
4. Tap on the Highlight text format button located in the toolbar (i.e. the (A) button).
5. Select a color different from the currently displayed.
6. Observe that the selected text is displayed with the color picked.
7. Tap on the ⚙️ button.
8. Tap on "Text" button.
9. Select a color different from the currently displayed.
10. Observe that all text is displayed with the color picked, including the previously highlighted.

Expected behaviour

The highlighted text should preserve its color when setting text color to the text block.

Actual behaviour

The color of highlighted text is not preserved when setting text color to the text block.

Screenshots or screen recording (optional)

ios-highlight-text.mp4

WordPress information

• WordPress version: N/A
• Gutenberg version: N/A
• Are all plugins except Gutenberg deactivated? N/A
• Are you using a default theme (e.g. Twenty Twenty-One)? N/A

Device information

• Device: iPhone 13 (simulator)
• Operating system: iOS 15.4
• WordPress app version: trunk

[SiobhyB]

Tested and confirmed I could reproduce this on iOS in the latest version of the app (23.8.1). The issue is not reproducible on Android.

[geriux]

I have a fix for this that I'm working on currently so I'll remove the High priority label.