I'm almost certain this has been suggested before but if not:
http://img7.imageshack.us/img7/9229/shieldhealth1.png
Blocking attacks brings up the shield health meter underneath your character.
http://img197.imageshack.us/img197/5030/shieldhealth2.png
Taking damage lowers the shield health meter, obviously.
http://img221.imageshack.us/img221/963/shieldhealth3.png
Broken shield.
http://img835.imageshack.us/img835/5553/shieldhealth4.png
Shield not in use, but regenerating (shield health meter transparent)
http://img692.imageshack.us/img692/707/shieldhealth5.png
Shield health fully regenerated (shield health meter disappears)
The point of such a meter is to allow more precision when blocking. There are ten bars. Each half a bar represents 5% of the shield's total health. Shields health meters constantly go up as they constantly regenerate.
This will also help alleviate some confusion about the shield colors. If it goes in I also propose a menu option to turn it off, because some may find it annoying.
What's more confusing, a random bar who's role has been fufiled or a color coded system most players learned in kindergarten, red being bad and blue being good? The bar would just an annoying waste of OOO's time imo