So I read somewhere that you cannot describe an item with two colours using te-form. eg そのシャツは赤くてしろいです. Just want to verify if it's true, and if so, how would you link them? Would using the noun form of colours be correct? eg そのシャツは赤と白いです。
In general, it is true combining color adjective with te-form would sound unnatural like そのシャツは赤くて白いです. It sounds like the shirt is red and white, which is not possible. That said, practically, it may well be understood as Red and white are used for the shirt (there are red part and white part in the shirt).
Using noun form is fine, but you should use nouns for both: そのシャツは赤と白です.
My impression is that usually the description is more specific.
- そのシャツは白地に赤のロゴ入りです The shirt has a red logo with white background.
- そのシャツは青と黄色の縞模様です The shirt has blue and yellow stripes.
Color A と Color B is more likely when it is understood how they are used.