Pinkwashing is a word that refers to companies that claim to be supporting breast cancer charities in order to make themselves look good, but whose main aim, in fact, is to promote their own products.
The term 'pinkwashing' was coined by Breast Cancer Action, who were concerned that companies who exploited the colour pink did not make it clear where any funds received would go, or that produced products that were known to be carcinogenic. Companies that have been criticised by the charity include several car manufacturers, including Ford, Mercedes and BMW (because cars produce air pollutants linked to cancer), Yoplait, which produces yogurt from milk treated with a hormone that is linked to breast cancer and KFC for selling its fatty fried food in a pink basket (high-fat foodstuffs are linked to cancer risk).
The word 'pinkwashing' clearly comes from 'whitewashing' (which, as the OED says, 'implies a false appearance of good'). Before pinkwashing there was greenwashing, where companies claimed -- without being able to back the claims up -- that their products supported the environment.
There's an interesting article on pinkwashing, including the origin of the pink ribbon as a symbol in this Forbes article.