WHAT IS IT?
Colors in English are used to describe nouns; they do not take plural forms, and you must place them after the verb to be (is/am/are/was/were/been) or before the noun you want to describe.
- The car is blue (after verb to be)
- The houses are purple (after verb to be, notice you said purple, not purples)
- The gray computer arrived yesterday (before the noun)
- Those yellow birds sing beautifully (before the noun, notice you said yellow not yellows)