Coloring Text (speech bubble)

There is a full documentation there : https://docs.unity3d.com/Packages/com.unity.ugui@1.0/manual/StyledText.html

With it, you can make text bold, italic or even a different size. For example yellow text would be <color=yellow>Text Here</color>.

List of supported colors

If you don't have the color you want in the above list, you can use an RGB picker (like https://rgbcolorcode.com/) and use <color=#code you got>Text</color>.

For example:

Here we see the color I chose is A3FFE0, so<color=#A3FFE0>My Text</color> should be used.