VERTEX STUDIO: I made a complete vertex color painting solution for Godot.
Some features: Adjustable brush w/ falloff, color, swatches, masking and selection tools, snapshots and vertex groups, debug views and overlays, channel selection, fill/erase all or just the selection, color replacement, etc.
A dream tool to make PS1/N64/retro games with Godot. Can also be used to blend textures w.e. game, just setup the materials to use the vertex color as blend factor.