Full Site Editing: Site title block color setting not working properly

[alaczek]

Description

Setting the color of Site Title block has no effect in preview.

Step-by-step reproduction instructions

1. Open the site editor and start editing the site header.
2. Select the Site Title block and open the color settings in the sidebar.
3. Change Text Color. Not the color is being applied in the editor.
4. Save and preview the site in a new tab. The selected color is not applied to Site Title.
5. In order to change the site title color in the preview I needed to Select the Header template part and set the Link Color.

Expected behaviour

I expected the text color set on the Site Title block to be visible in the preview, and override settings of parent template part/parent blocks.

Screenshots or screen recording (optional)

In this demo I set text color on:

1. Site title - no effect in preview
2. Group (parent block) - no effect on site title, changes color of nav menu links
3. Header template part - changing text color has no effect; changing link color finally changes site title color.

WordPress information

• WordPress version: 5.6.2
• Gutenberg version: 10.1.1
• Are all plugins except Gutenberg deactivated? Yes
• Are you using a default theme (e.g. Twenty Twenty-One)? TT1 Blocks (also replicated in Seedlet Blocks)

Device information

• Device: Desktop
• Operating system: macOS 10.15.7
• Browser: Chrome 88.0

[carolinan]

I was able to reproduce this.
This can be solved with #29021 and adding the link color option while setting the text color to false.