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.
Some examples:
{F8330016}
{F8330015}
{F8330014}
How it works:
{F8330111}
Useful for bright themes:
{F8330126}
Same in Krita:
{F8330921}