#105811 added the screencastMode.mouseIndicatorColor setting representing a color

• open the JSON settings (JSON), add "screencastMode.mouseIndicatorColor": "#ff00ff"
• see that there's a color decorator and that there's validation if you change the value to an invalid color

Now open the same setting in the settings UI:

• enter an invalid value #foo. No error
• a color decorator would also be nice

The color support in JSON comes from annotating the configuration schema with "format": "color-hex"