The secret of a mushroom painted by a greenish-yellow color is in the timing.
The color you pick for your painting is determined by how long you wait before you put the paint on the mushroom.
The longer the wait, the brighter the green will be.
The colors on mushrooms are a combination of red and yellow and the timing determines the brightness of the colors you choose.
When the color is the same color as the paint, you’ll see a clear yellow.
When it’s different, the greenest color will be the most vibrant and darkest.