We recently moved into a house and we have a tennis court, and recently I have noticed several small hairline cracks that I do not think were there previously, please see attached picture. 1. Is there a way to fill these cracks? 2. If they are not filled will these eventually grow wider? 3. The tennis court is green, please see attached image. Anyone know if this is just concrete painted green or if it is some special type of concrete? Thanks in advance!