What color is the Mutants Headquarter?

[mmartino]

Hi fellow fans I wanted to make a custom Mutant Headquarters but am conflicted as to what color exactly is the headquarters in the show. In some shots in the show it looks like its a light green and in some it looks like its mustard yellow. in the intro its a greenish tone. When i think back without looking at pics i think mustard yellow. please help fellow fans.