So birth control pills are in different colors because they want you to choose their “brand” – the brand can be generic or name brand. Name brand is more expensive because they are the original.
Also, some packs have 4 different colors, some have 2, some have more. If there are 2 color pills. usually the 3 weeks of 1 color are the active pills and the 1 week of the other are the sugar/placebo/bleeding week pills.