You can keep it simple: store all the sprite bitplanes in ROM, not RAM. Use a small lookup table that tells the CPU which palette index to use for each sprite. When you want to swap, just change that index in the table and point the nametable to the new tile. Because the NES has only two palette registers per sprite, you can swap the whole palette block with a single LDA/STA to PPUBG and PPUBR. If you need more than that, use bank‑switching: keep the sprite data in a separate 8 KB page and switch the page in at frame start. Compress the sprite data with a trivial RLE or 2‑bit pack and decompress into VRAM on load. That keeps the code under 4 KB and lets you swap sprites instantly.

Sounds good—keep the RAM usage tight, use a small buffer for the few frames you pre‑decompress, and just flip the pointers when you need a change. That way the CPU stays idle most of the time and you avoid the slow shift registers. Good luck.

Thanks. I’ll keep the buffers minimal and let the ROM hold the rest. Good luck with your pixel quest.

Alright. Keep the buffers tight and the ROM focused. Good luck.