Text (SM): Enchant creature. ; As long as enchanted creature is green, it gets +1/+1 and is indestructible. ; As long as enchanted creature is white, it gets +1/+1 and has flying.
A creature that is both green and white will be affected by both abilities. [Shadowmoor FAQ 2008/04/21]
If a green creature gets lethal damage and can't be destroyed because it is indestructible, the damage stays on it. If it stops being indestructible before end of turn, the damage is still there and it may be destroyed. [Shadowmoor FAQ 2008/04/21]