Sprite Palette Swap — Recolour Ramps and Team Colours
Every recolour here is a palette transform: pixels keep their palette index, so two frames that shared a colour still share it and the darkest shade stays the darkest.
- PNG framesMeasured· Pillow
- PaletteMeasured· re-import
- pixel-lab.jsonUNVERIFIED
What it does
- Ramp swap: selected source colours map onto a target ramp by position in lightness, never by nearest colour.
- Auto ramp from one base colour, keeping the source ramp's lightness steps.
- Team colour batch: N variants (red, blue, green … or any #RRGGBB) exported as one ZIP with a folder and a .gpl per variant.
- Hue-range replace and status presets (frozen, poison, burn, ghost, damage flash), labelled as recipes.
How to do it
- Drop the frames.
- Pick the colours of the ramp to change on the palette.
- Choose a ramp, base colour, hue window or status preset and preview it.
- Apply, or export the team variants.
Outputs and how each was checked
"Measured" means the downloaded file was opened again outside the page (Pillow, numpy or an independent parser) and the property was measured. Loading these files in a game engine was not tested.
| Target | Files | Check |
|---|---|---|
| PNG frames | anim_N.png · 1×–8× nearest | Measured PillowEvery exported colour re-read from the PNGs lies inside the locked palette. |
| Palette | .gpl · .hex (Lospec) · .json | Measured re-importEach format was exported and imported back through the UI: 16 → 16 colours. |
| pixel-lab.json | generic frames + palette | UNVERIFIEDGeneric JSON; not loaded in any engine. |
Evidence
8 anti-aliased frames → one 16-colour palette with 0 exported colours outside it; an unchanged region identical in all 8 frames with dithering off and with Bayer 4×4; the anti-alias remover took 271 colours to 16 without moving a single silhouette pixel; integer scale, offset and 2.5× non-integer scaling detected exactly.
Limits
- Frames larger than 4096 × 4096 are refused: every pass runs on the main thread, and there is no cancel button yet.
- A sprite sheet is treated as one image; cut it into frames first (sprite sheet cutter).
- With a dithering mode on, the cleanup counts include dither pixels; set dithering to None first.
- The exported JSON is generic; importing it into Godot or Unity was not tested.
Questions
Will shading stay consistent across frames?
Yes. Recolouring rewrites the palette, not pixels, so every frame keeps the same index for the same shade; in the test, 4 variants changed exactly the 3 selected slots and left the other 13 byte-identical.
Is there a one-colour swap with tolerance?
Yes, the separate palette swap tool does a single colour with a tolerance and a shading offset.
Is it free, and do I need an account?
Everything on these pages is free and works without an account. There is no watermark and no export that is held back.
Are my sprites uploaded?
No. The Studio decodes, packs and exports in this browser tab. Projects are autosaved in the browser (IndexedDB) and can be saved as a .nerulio file.
Does it need Aseprite or an engine plugin installed?
No. .aseprite files are read and written in the browser, and each engine bundle carries what that engine needs (for Godot, the import settings and scene; for Unity and the Godot TileSet, a small editor script).