Theme custom color preview swatches always render as solid white on Native Android

When customizing theme colors in the mobile app, all color preview swatches display as solid white regardless of the custom hex value entered (e.g., #F4F4F6). While the underlying text input accepts and saves hex values properly, the visual preview boxes fail to render the selected color, making it difficult to distinguish between dark and light color tokens visually. Expected Results The preview swatch box next to each hex input field should reflect the actual color defined by the hex code. Actual Results ​The color preview swatch remains solid white for almost all background, fill, and border tokens.

Settings > Look & Feel (Application) > Configure (Theme colors) Locate any color token entry (e.g., --embed-background, --markup-mention-fill, or --markup-everyone-fill). Type or select a custom hex code. Observe the color preview swatch attached to the input field.

Version 2026.10.100, Beta 4, Channel Beta, Build 633, Android 15 (arm64), Device vivo V2310, Locale en-US, Push fcm, Flutter 3.47.7, Dart 3.13.5