Difference in color presentation between coder + builder

OS (e.g. Win10): Win10
PsychoPy version (e.g. 1.84.x): v2021.2.3
Standard Standalone? (y/n) If not then what?: y
What are you trying to achieve?: Understand the difference in color presentation between coder and builder.

What did you try to make it work?:
I am attaching two files: one in builder view, and the other in coder view. Both have the exact same code (though in the builder view, I am using a code snippet to draw the stimuli).

The coder view accurately portrays what I want to do: a square grating that is yellow/dark yellow.
Based on a previous troubleshooting toy code from @djmannion, the test code increases in opacity with every key press.

What specifically went wrong when you tried that?:

Builder view grating is in yellow/black (first image).
Coder view grating is in yellow/dark yellow – as intended (second image).

How do I achieve what I see in coder view, in builder view?

Even if I were to convert the builder into coder view, the color issue remains. I’ve checked as many differences as I could find. Blendmode is “add” for both.

Note: I also have to add this code snippet in builder view to make sure pixels out of range aren’t marked with noise. I’m not sure why, however. Turn off artificial noise when using blendMode 'add' - #2 by djmannion

Thank you so much! Please let me know if you need additional information or something doesn’t make sense.

In builder view:
yb_test.psyexp (12.8 KB)
In coder view:
drawOnceTwiceThreetimes.py (2.7 KB)