Here are some pictures to help guide people in solving the tiles puzzle.

 

first get the tiles to all but one of one color.

tiles 1

then flip that tile.

tiles 2

then flip each one of the resulting tiles.

tiles 3

then flip each one of those resulting tiles of the lesser color.

tiles 4

then again flip each of the tiles of the color you origionally got down to one of, and after you've done all of them you should have solved the puzzle.

 

Hopefully you wont forget which tiles you've already flipped and which ones you need to flip yet on the last one.

and they are png like you told me to do several months ago.

I think the problem for most people is getting to the point where they only have 1.

Thanks for these images, but I'm not sure of a practical way of using them. As zaaps said, a lot of people have trouble with getting it down to that point anyways, and even then it would be much faster to just force the last tiles, no?