As a person who is colourblind with reds greens and browns, I can tell you that it is a hindrance. Looking at Hickory's screenshot was bad enough, playing the game like that would be annoying. Incidentally, I have the same trouble in IWD1 where thief skills are shown active by a poxy red border that I can barely see. I usually end up turning the abilities on and off and checking the message window to make sure they are still active. In the case with the selected ammunition in BGEE, I would have ended up picking up the ammo I wanted to use and put it back in the quiver to make sure that is the ammo I would be using but why should I do that when in the original game, the bright border highlighting the selected ammo is clear and saves a colourblind person like myself from messing around like that. What isn't broken shouldn't be fixed, the selection border should have been left in.
Playing though Neverwinter Nights on the other hand was so aggravating it almost made me a follower of Ilmater!!!! Two areas in the hordes of the underdark had puzzles where you had to select colours in the right sequence. In the first area, I couldn't tell the difference between the yellow and light green. Because of that, I also couldn't tell when the colours changed and cos of that, I kept messing up the combination. I was able to get past the puzzle with some serious save scumming though. The second was even worse. It was the area where you had to teleport over a bunch of islands in a lava pit and you had to flip 3 levers to make the 3 statues radiate the same colour except I couldn't tell the difference between two of the colours and I was stuck in that area for a few hours!!!! First, the puzzle was a stupid idea as it was, second, not being able to tell which statue was radiating what colour made it worse, third, if I had the wrong combination (and I did a LOT!!) I needed to back track and flip levers AGAIN and fourth, because you could only teleport to certain islands at the right time, it made backtracking tedious AND time consuming.
Either the devs don't consider these things, they had their brains turned to liquid shit by mind flayers or they are followers of Loviatar. Whatever the reason, I wish they would stop it already.
I don't know if I have a mild form of colorblindness, or just plain blindness, but I constantly mistake the green and white gems for each other in the Bejeweled games. Oddly, that seems to be the only game I have this problem, and it may have to do with my mind equating the shapes rather than the colors. It gets annoying to have a chain broken because I accidentally pick two greens and a white for example. Thankfully at least PopCap includes a colorblind mode in several of their games.
And no, I don't think the devs necessarily consider people with any disability - at least not until the mid to late 2000s when gamers started getting "old." I still see far too many games with beautifully detailed but tiny graphics (Sacred 2 comes to mind) and text so small you have to sit two inches from the screen to see it. The Sims 3 is a prime example. My system can run the game at full HD, but the UI doesn't scale properly and I have to run the game in 1280 x 720 or 1366 x 768 just to see what's going on and to be able to read the text.
Another thing I wish they would do is properly scale the UI if you have increased the DPI scaling in Windows. I bumped mine up to a modest 115% and even within Windows you have text that no longer fits in a dialog box. So you can read what's there, but have to deal with cut off. It's even worse when it affects the placement of command buttons and you can no longer press the OK button, for example. Chalk me up for another Ilmater follower. Hope the sign-up perks are worth it. =)