I have zero issues reading the text. Not sure why people are having problems to be honest. I said other. I would to see the HUD colour be able to be changeable to what ever you want within the options panel. I would likely keep it as is.
I think a part of it is that Frontier's choice of the HUD color, orange, requires multiple subpixels to display, whereas using a color that requires a single subpixel to display (red, green, blue). On current generations HMDs, this simply makes smaller text harder to read, simply because there isn't enough pixels for higher resolution, leading to what is effectively 20/40 vision in-game.
Another part of it, at least for Vive users like me, is that for some reason when Elite: Dangerous sends graphics to SteamVR, there seems to be a boost in brightness, making the game look washed out. Yesterday, when I gave the "Night Mode" setting a try, I noticed an immediate jump in legibility, even in the comm panel, which I used to have to lean forward to read. It also helps that I keep my gamma correction settings low, so I can experience "true darkness" in the game.