This let me away with simply 'seo pinc'. Should it have?
Technically yes. It depends on the context. Tha seo pinc is describing something as pink. If however you were identifying something as pink then seo pinc would work.
So if I've got my contexts right. Tha seo pinc means 'this (thing) is pink' whereas Seo pinc would be 'this is (the color) pink'....yes?