This varies widely between brands. Farrow and Ball - Contact customer service. Sherwin Williams - Generally listed on the back of each color on the paint fan decks, or click "details" on an individual color listed on their website. Valspar - Valspar lists colors on the fan paint deck. Benjamin Moore - Search for the specific color on the BM website and it's listed there, and it's also listed in the index of your paint color fan deck.