Which solar cover is better lue, black, crystal etc.

[cnk]

Which solar cover is better? The blue, blue with black, blue with silver, clear, or crystal clear?

[matt4x4]

If you can get one with a Silver bottom, it will help reflect the heat that's trying to rise (escape) back down into the water.
If you get a clear one and use it during the day, it will help heat your pool by allowing the rays to pass to the floor of the pool.
If you get a dark one and use it during the day, it will attract more heat but only heat the top couple of inches of your water.
If you get the regular blue one you don't see much of any of the above benfits so it is the worst choice.