I recently got the question whether its possible to have custom background color in derived cells. The basic answer is: yes.
A while back we introduced some very basic concepts to use simple prefixes in your text to either show an emoticon (a dedicated expressive small image) or change foreground and background color. The rules are very simple:
- The expression has to always at the beginning of the text, you cannot place it anywhere in the text line (it has to "prefix" the normal text)
- The prefix always starts with [ and ends with ]
- The prefix either matches a known textual emoticon or it encodes a background color or optionally background and foreground
So a very simple text that your property may return is:
"[!] Some text"
That results in:

Colors are encoded using an @ prefix followed by a color, either as #DDDDD style or as 3 values for Red, Green and Blue, separated by colon. So
[@#FF00AA] Other text with colors
will give:

Foreground is given optionally as second argument, so:
[@#FF00AA:255,255,255] Other text with colors
will result in:

Finally the table of all supported emoticons (also available in the metamodel guide):

Ah, attached to this article you will find a simple 2019 R3 project which you can use to play with. It contains two string properties to enter text with prefix and two derived properties to show how it would look like:

Happy Scripting
Jan