When your skates cut into the synthetic ice, that cut loses a bit of its pigmentation (just like when you bend a piece of coloured plastic, you will notice it loses pigmentation at the bend). This is not as evident on the white tiles because there is very little contrast. Whereas on the coloured tiles, that contrast is more pronounced as it is a light marking on a blue surface as opposed to a light marking on a white surface.
Click here for normal blue tile wear!
Shavings and cuts are OK!