^ This is because sharpies use a certain type of oil as the base. It is what makes them permanent and it is why you can sometimes remove sharpie with sharpie. When that starts to happen the oil to pigment ratio is off so your diluting the pigment you already laid down.

I am full of useless info!

I think a white bike with a few orange accents would look good. I know it's not a bicycle but good inspiration