Try playing with the white balance on the camera. Some cameras will have an option to set it manually, but some will only allow you to choose between the presets. If you can do it manually, set it while pointing at something white like the sand.

Check out the canon S1 IS. Its a very nice camera and they are getting cheaper since the S2 IS just came out. Also, the Nikons are decent for a cheap camera. I have a coolpix 3200 that can take some decent shots. You could probably pick one up for 100 or less on ebay.

cs