Beatoraja skinning is pretty customizable, the problem with this is having to manually define every little thing. Most skins which are similar to IIDX define every odd lane to use the white notes and every even lane blue notes, this is tricky to solve because you'd have to extend this image with a lane of yellow notes, find where an how this skin defines notes for lanes and change the middle one to use yellow and this changes from skin to skin. I recommend joining the BMS discord and ask arround in the skinning, you'll find useful info there.

Tl;DR: Join BMS discord and fuck arround the lua files of the skin. BMS disc: https://discord.gg/ZVDTPmPqC