There's definitely more to do with this palette, I could use it for future art aswell for sure. It was really coincidental while trying the idea itself for the first time.

The 2 pinks on the background are from the same palette with lower opacity.

That's a lovely presentation!

This palette is pretty, especially with the two pinks, do you plan to do anything more with it? (I have a soft spot for limited-palette games.)

Fixed

It would help to expand the background so that it's easier to see the edges of the leaf in context. Alternatively you could just make the background transparent, but then your AA might look a little weird since it looks designed for white.