Surface color change

Grasshopper
1

Hello, I’m a beginner, I can’t find a way to differentiate the colors of the two types of cylinders such as one yellow and one blue.

POZZO_PALI_RETTANGOLARE.gh (23.0 KB)

2

POZZO_PALI_RETTANGOLARE_ME.gh (22.2 KB)

Canvas at 12;31;53
Canvas at 12;31;53725×755 274 KB

3

thank you