Just installing a new one. The first water feed pipe I bought was the wrong size (1/2 IPS x ballcock), so I bought another (1/2 comp x ballcock). So this new one is banded with a a red band. Did I screw up the plumbing because red means “hot”, and I ran cold water to the toilet. The other one’s light green.
What do these band colors mean?
Just a guess, but my suspicion is that green means IPS and red means compression for that manufacturer to help the store people keep track of otherwise similar looking items.
Of all the toilets I’ve fixed or installed, I don’t recall any colored banding as part of the supply lines, but I have seen different color stripes on the labels.
You need 7/8" closet supply by whatever valve you have at the wall. Most likely 1/2" unless your plumber was a fool.
You can tell the 7/8 by the grey plastic nut on one end.
NB, some cities require hard supplies and don’t allow braided ones. Unless you are selling the house you can disregard that.
I found a blue banded supply line with a 3/8 comp. on one end and 1/2 IPS on the other. Thus:
Green = 1/2 IPS
Red = 1/2 compression
Blue = 3/8 compression
I have a mixture of all three in my apartments, what does that say about the plumber?
One head’s up fpr those using big box - this is (yet another) gotcha.
As noted by MikeG, closet (aka toilet) supply should be 1/2" supply (smaller will have less power in the flow, and take longer to refill)
I, being accustomed to 3/8 everything (even the ice maker in the freezer) bought 3/8 vlve and hose.
Then remembered the 1/2" rule.
HD has 1/2 x 7/8 hoses (their 7/8 connectors vary in color) BUT the hose on the 1/2 x 7/8 is 3/8 - yep, a 1/2 fitting on a 3/8 hose.
I kept the 3/8 hose and added another “to do”. Going to have to get to a real plumbing store pretty soon.
For those puzzled: just as a chain is no stronger than its weakest link, a hose will not pass any more water than the smallest diameter component - the 1/2" and 7/8" connectors are bot limited to the 3/8" hose.