(Localization) How to make a template with more specific colors ?

Hi, I want to make a template with more specific colors but I have no idea how to do that, the only colors that work are solid patterns

I also tried cyan and magenta, but they did not display correctly.

Rich text supports colors in hex format such as

We are <color=#ff0000ff>colorfully</color> amused

https://docs.unity3d.com/Packages/com.unity.ugui@1.0/manual/StyledText.html#supported-tags