Hey guys, just some curious thoughts that hopefully aren't extremely simple and make me look retarded hah. (oh well if it does)

I tried looking this up with no such luck so I have come to here. I had always wondered why oceans in different locations had radically different colored water. I figured it had to do mostly with the sand, with regards to color and maybe how much is floating in the water. But, I feel like many places have similarities with both of these, yet are still different. Does temperature have a factor? Also, I feel like pollution shouldn't affect it that much, as the ocean is enormous, but might affect locally. Another guess might be river runoff?

Just throwing guesses out there.

Thanks for info boys,