Think of it like the older folks who always drove Buicks. Younguns actually made fun of them for it but never stopped to wonder why that is. Since Buick not long ago was ranked right up there in quality with cars costing twice as much and that always got top honors (true story!) Maybe those older folks were on to something. I mean, if you've had 70-80 years of success using a certain thing should you change just to change?
I admit I've settled on the line colors I prefer. Just like the fly you have faith in catches more fish than the others, when the color of the line leaves no doubt that it works best for you than use it.
No need to brag or boast... it's what you like, that's all.
Using bright lines when I want them to be seen makes sense to me and dull lines when I want them stealthy also makes sense to me and when you get down to it that is all that matters really (until you start waving those bright lines around the spooky fish I'm working!)