How to change tiles' background color in Windows 8.1 start screen?

Have you checked in the Store? There are a number of freebies in there: http://apps.microsoft.com/windows/en-gb/app/custom-tiles-maker/6192f3b0-03e5-421c-82f4-33ae16537559

Does anyone really believe after all these questions, all these posts, all this ado they don't understand the problem? I really believe it is something other than understanding the problem. What I don't know.

The answer lies somewhere in shell32.dll

Try having a go with this freebie: http://www.pcworld.com/article/2044561/review-generate-better-looking-windows-8-start-tiles-with-oblytile.html

I wanted to be able to change the color tile to coordinate and make them look nicer with whatever background I choose. When I click on the tile in my start menu there is a choice to customize the tile. I clicked on it and nothing happened. How do I do this? Its very frustrating that you have no control over what color they can be.