Unfortunately we can't modify the game until the review period is over. But yeah, I was debating if that mechanic was a bit too strong. If you have an NFT with a high value and a white background, the fact that your drawing begins with a white background already is worth a lot of money. I tried making it so only modified pixels are worth money, but that ended up being too difficult to get much value out of.
However, the safeguard against higher value NFTs is that they won't instantly sell, so if you want a player to actually buy your NFT, just a white square isn't going to stand out much. Unless of course someone wants a white square to farm money :)
There's also a bot that runs on the server side that randomly buys NFTs every once in a while, so the fact that the player base is pretty small means you'll probably get a free buy from the bot.
I'll brainstorm and see what we can do to make it feel a little better after the jam is over