How do you understand the errors please on Builder

Hi, how can i read and understand the type of errors that builder sends me please i just have a very small script with two routines took a screenshot of it !
thank you very much in advance
the first screen is just a figure and im forcing this one to disappear when the persons clicks on the letter f and the second routine inside this same script is just a empty screen that should appear on the screen!

This is an error to do with setting the color incorrectly for one of your text stimuli. What value are you trying to set it to?