Here is my CTC-7 with grey faced 21CYP22, with Philco 21FBP22 green faced tube sitting on top. The monitor to the right is a Sony security monitor, with NTSC comb filter decoder.
http://www.videokarma.org/showthread.php?p=2998927
Grey faced 21AXP22 has similar color to the CYP tube, where anything with a green sulfide set of phosphors looks more orange-red than true red to my eye. We'll see what the green faced 21AXP22 in the CT-55 ends up looking like, I assume it will have similar response to a 15G.