Currently, RPA Express does not support color image detection (cf Image detection accuracy - even higher!).
Attached is a custom action that can be used as workaround. This script returns the color under the mouse as (r,g,b,a) (int value between 0 and 255). You can easily change it to return the color at a desired location of the screen. What is left is to compare the color with the targeted one and to click on the object (regular mouse click) if the condition is fulfilled.
Hope it solves your issues
getColorAtMousePos.txt (1.5 KB)