No, colors are not considered proper nouns.
Proper nouns are specific names that refer to unique entities, such as individual people, places, organizations, or sometimes brands. They are always capitalized. For example, ‘John’, ‘Paris’, or ‘Microsoft’ are all proper nouns because they denote unique identities.
In contrast, colors like ‘red’, ‘blue’, ‘green’, and ‘yellow’ are common nouns. They describe general categories of things rather than unique individual items. While you may see colors capitalized in certain contexts (for instance, in a brand name or to start a sentence), they remain common nouns because they represent a general idea rather than a specific entity. Therefore, ‘red’ refers to any shade of red, not a unique or proprietary red.