Just looked in my coolant res, seems to be a bit milky looking. Not green anymore, looks more greyish green. Showed my shop a couple weeks ago they said it should be fine to drive around but to bring it in when I get a chance. How serious a condition is this?

 

Are you losing coolant? Is there steam coming from your exhaust? Check your oil too, if it seems to be filling up then coolant is getting into the oil pan.
If you've got the gauge for it, do a compression check on your engine. Normally, compression should be in the 150 psi range. If there's a blown head gasket or cracked block you'll know it from the severe drop in compression on one or two cylinders. If you're not lucky then you could have a cracked block. The trouble is the compression test will only confirm a loss of cylinder pressure. You won't know if it's due to a gasket or cracked block until the engine is torn apart.

 

Bubbles in your coolent reserve bottle equals blown head gasket and or warped or cracked head. If you see air bubbles while it is running.