I tried to use Google search engine to find any software that can change the clear color of any OpenGL game, but I did not find such software.
I want to know if there is any software that can do that.
There are OpenGL games that invoke glClearColor with constant numbers and they don't give the user any option to change the color of the background without resorting to hacks.
I believe that you are speaking of the Alpha channel in OpenGL. To my knowledge, there is no way to change it without making wholesale changes to the other colours on your screen. The Alpha channel is used to hide things like portions of sprites in games and other things which are not to be displayed. They are, in effect, clear and invisible. Hacking the OpenGL settings to colour the Alpha channel would result in a rather messed up screen, as stuff that is supposed to be invisible, would now be visible, leading to all kinds of a mess.
Hope that helps.
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