If you can get a piece of it into a paint
store-Sherwin Williams, etc.- they can make a computerized match. I you can't get a piece to take in get the paint
store to loan you a color wheel which will have all of the available shades of all the colors or if they don't have one to loan take color sample chips that look close and if you don't get it right go back and get... lighter -darker-greener-yellower-what ever till you get as close as possible. Color matching is the nemesis of most painters. Best of luck to you.