About Keywords used on Product Pages

Say, I have 3 same products of different colors.
Should I use different keywords for each listing title (case A), or all uses the same, but the color makes a difference (case B)?

Example:
Case A:
Product 1: keyword 1 keyword 2, red
Product 2: best keyword 1 and keyword3, blue
Product 3: keyword 2, buy green keyword 1

Case B:
Product 1: keyword 1 keyword 2, red
Product 2: keyword 1 keyword 2, blue
Product 3: keyword 1 keyword 2, green

Which one is a better practice?

Thanks in advance.