Color Temperature Variation of Light Modifiers

There is now a huge range of lighting modifiers available, some quite inexpensively. I've noticed, though, that the color temp of the modifiers varies a fair bit. My Speedotron reflectors, Photoflex, Fotodiox 32" beauty dish and strip lights are all very close to 5K, although the big strip boxes go a little blue near the ends. My 8x36" LA softbox strip lights, a Fotodiox 48" Octobox, and a small octobox require a 1/4 CTO filter to match the other light sources. Of course for BW none of this matters much, but if you're shooting color, you might want to check whether your modifiers vary.

My Photoflex Litedome softboxes do cause a significant yellow shift compared to the bare tube.

Mine is about 20 years old. Recently, I bought a new front diffusion screen for about $15 from Photoflex. I was surprised to find that the light matches that from my Speedotron metal reflectors. My LA Softboxes, which are very nicely built, came in at 7500K.

Hmm... mine were bought in 2005 I think. I wonder if 12 years is enough to yellow them this much?