How can I show a validity by a prompted symbol in colour?

[Maray]

I need to have symbols in GREEN, RED and/or AMBER thus showing a
user-friendly validation of results generated from formulae.

 

[Pete_UK]

Bob Phillips shows how to implement a traffic light display here:

http://www.xldynamic.com/source/xld.CF.html#lights

Hope this helps.

Pete