Except in some tourism promotion advertising.
Usually it is tan, but occasionally brown.
Sometimes it’s tan and gray. I call these crab balls. They’re created by a critter that digs tunnels looking for food.
Occasionally it’s brown and psychedelic.
[Begin update Sep 13 2011]
I was asked if the photos show the true color of the sand and if they were taken in Hua Hin. Yes to both. They were shot at the end of the soi that is on the south side of the property which hosts the Cicada Market. This photo shows the distinctive stone beach entrance, the dry tan sand and the wet brown sand.
[End update Sep 13 2011]