osu! paints the hit circles by multiplying hitcircle.png with the combo colours from skin.ini. Change them here and press play — the preview above is the real result. Then paste these lines into the [Colours] section of your own copy of the skin.
Nothing is uploaded and nothing is rebuilt — the skin stays the author's. This edits four lines of text.
Read straight out of the .osk itself — not from the forum post, which is often out of date. We inspect the archive over HTTP range requests, so this costs about 100 KB instead of downloading the whole 848-file skin.
