I'm typing on my iPad at night using an app that has a black background and gray text, but when the on-screen keyboard pops up it puts a lot more light into the room due to the fact that the "keys" are a much lighter shade of gray in large solid buttons.
How can I adjust the brightness of the on-screen keyboard without affected the rest of the screen which is already at the right brightness based on the overall brightness of the screen itself? I am thinking the ideal case would be if I could make the keys on the on-screen keyboard a much darker gray and the text on the keys darker to match. That is, all I need to do is change the color of the buttons and text on the on-screen keyboard, however I haven't found out how to do this.
I have seen some places where it is possible to install a different keyboard such as GBoard but these don't seem to have the flexibility to arbitrarily set the actual color of the keys and text; instead you are limited to whatever color themes they provide or to use a background image which has white keys overlaid on it. (update: Apparently you can do some limited changing of colors, that is, you are limited to 16 or so different colors. But at arbitrary times it seems like GBoard forgets the customizations to the color theme and reverts you back to the default!)