Was the market failure within the rec lines?
What market failure?
If you're accidentally losing ballast you need to reconsider the system you are using. It's unacceptable, IMO. My ballast is not coming off me unless I decide it is.
Regarding the example in your OP about...
In a potential emergency wondering if maybe I should ditch some weight, a small part of my brain would worry about the weight color.
Well, I'm pretty sure that falls under the "Darwin Awards". If a few dollars of lead or the color of the pocket is worth more than someones life then they really need to reevaluate what's important in life.
In terms of training, I'm not aware of this being an issue. Ditching ballast is a basic open water drill, typically performed first in a pool, then maybe on an open water platform or at a benign site with great viz in shallow water, ~20 ft. After that, what other class requires you to ditch ballast?
In the real world, here's the deal...
If you lose or run out of breathing gas at depth you get to the surface as quickly as possible. Ditch your ballast, hell ditch your whole rig if you have to (Don't forget to keep your airway open). I don't care how much it cost or what color the pocket is. It ain't worth your life.
If you're on the surface, but are unable to remain buoyant, ditch your ballast. Again, I don't care how much it cost or what color the pocket is.
If after this emergency, you gain your composure and decide you're going to go back down (unlikely) then the practicality of you actually finding your pocket is going to have a lot more to do with the dive than the color of the pocket. Were you drift diving? How far did you travel from the point you dropped the pocket until the time the boat picked you up? How far did the boat drift after they picked you up? Are you making mental notes of this during the emergency? Did you mark a GPS location? Now does the color even matter?
If you want to make your pockets a bright color, do it. Seems like a good idea for your concerns, but to call it a market failure seems like a stretch. My 2 year old, once bright red 5 pound soft led weights are now basically brown. Do I replace them because they're not bright anymore? And if I did, would I want to pay a premium price for a bright color? Nope. Although I am surprised someone in the scuba manufacturing business hasn't jumped on this idea. It's like taking an identical mask and throwing a brand name on it and selling it for double the price. All to common in this industry.