I am not a fan of the color "in the middle".
Whatever you put there will absorb heat. Also, it honestly looks like crap. You have paperwork, that'll tell you what color is in the light. If your prep the color before the
load-in, there shouldn't be confusion about what color is in the frame.
My $.02
Sean is absolutely right. If you are concerned about know what color it is to change the color, you shouldn't label your color through the center of the cut. Why? No matter what you use to write on the cut, be it
sharpie or
grease pencil it will just sit there and absorb heat and eventually melt the
gel. Yes, writing through the center of a cut will cook the
gel faster than writing in the corner. This means that if you write in the corner, so save on consumables.
I just don't think that you need to be able to tell what color is in a
fixture by looking at it from the floor. For those of you who said you put the label so that it is visible when in the frame, but small, what is the
point, that you can't read from the
deck! If you don't have good paperwork that tells you what color is supposed to be in each light, you had better have a chat with the designer!
The other huge advantage to labeling in the corner is for when you have to
trim a cut for a different
unit. Sometimes you just need that one more cut in a certain size. Well, if you have a 10" cut handy and you need one 6.25" cut, you could
trim the 10" down. If you have labeled the 10" cut in the corner, it is very easy (if you pay attention) to cut the
gel down and keep the original label. If you have written through the middle, you end up with partial labels in odd places on the
gel. This can be confusing.
So, in the end, labeling on the corner of a cut will save you time and money