Growing up, the family enema bag used on me, and secretely by me, was the classic red enema bag, which remains my sentimental "family favorite".
After getting married, my wife had a yellow latex 2 quart delight, that I almost wore out.
When I visited NYC, I came across a 3 quart red beauty at Macy's that was truly irresitable. Wore that one out and later got another one, which I also wore out!
Then I discovered Sherema and got a black 4 quart enema bag with black tubing, which I wore out the hanger part, but can still use with an alternate hook hole.
Then I added a 4 quart orange/red bag with red tubing from Tyler Labs, and also a nice 4 quart white bag with white tubing, as well as blue, yellow, beige, pink and red 2 quart bags along the way, and even a challenging 10 quart "camping water bag".
More recently I got a 4 quart silicone bag, with silicone tubing and colon tube from Optimal Health, which is what I now use most frequently, (along with a 24 oz red bulb for my morning coffee enemas) and must rate as my current favorite because of being able to see the fluid level.
Regardless of color, I figure you just can't have too many enema bags! ;D