This patch adds ability to set up colors and size of background (transparency) checkerboard pattern in viewport and 2d editors. No new backgrounds, only changing colors in existing ones.
**This is not the background of the viewport, it is a transparency checkerboard that is turned on only in render mode, when the transparency mode is on. And also in 2D-editors, (image, sequencer, ets)**
Some examples:
{F8330016}
{F8330015}
{F8330014}
How it works:
{F8330111}
Useful for bright themes:
{F8330126}
Same in Krita:
{F8330921}