RefColorSync is an extension for Aseprite built for pixel artists who draw
from reference images.
It has two independent modes:
Cursor Color Sync — automatically samples the foreground color from
a reference layer as you move your cursor over the canvas. No more manual
color-picking every few strokes.
Auto-Paint from Reference — gradually fills in the empty (transparent)
pixels of your active layer using the reference as a source, one small batch
at a time. It never touches pixels you’ve already drawn by hand — every tick
re-checks the target before writing, so your manual work is always safe.
Highlights:
- Raster or Random paint order, with adjustable speed (ticks/sec and pixels/tick)
- Live progress bar while Auto-Paint runs
- Works with nested/grouped reference layers (recursive search)
- Sample from a single layer or the full composite
- Supports RGB, Indexed, and Grayscale color modes
- Clean, honest Undo — one Ctrl+Z undoes one tick, not the whole run
- Bounding-box optimization so large canvases stay fast
Fully tested in Aseprite’s real Lua runtime (not a mock), covering edge
cases like closing the sprite, deleting the layer, locking the target, or
switching frames mid-run.
GitHub (download + source):
There’s also a video walkthrough of the extension — I’ll drop the link
in the comments below once I’m able to post more links.
Feedback, bug reports, and feature suggestions are very welcome!