It's just stressed. Here, they turn a vibrant red/brown color in the wintertime, then return to normal in the summertime, unless they are stressed due to lack of water, in which case they remain red/brown.

I agree totally. I had a good size aloe vera in a 6 in pot, it also had 4 babies in the pot also. Summer came and I couldn't give them enough water, they turned a reddish brown similar to yours. I split them up, keep them watered and now they are returning to their normal green color.
Aloe vera needs generous waterings if it is in a hot and sunny location.

I'd also suggest your mix needs to be faster draining, it looks kind of houseplanty &/or clayish. I think it could use some improvements like adding 30-40% perlite or pumice to a C&S mix (I doubt that's what in the pot now).

My aloes grew on the ground and got direct sun in the morning to noon. They turned to be like yours in early Spring (which was hot hot hot). I dig them from to replanted in the pots and put them under the shade (between the bushes and under a tree). I put some babies' pots under the plant rack, no direct sunlight. Now, even hot summer, they turn back to green, especially the babies.

Goodluck.

Mine are in mainly shade too and they're green. If they get stressed or too much sun they turn orange. I vote for less sun.

sometimes it's sunburn. mine turned that color this spring when I first put them outside.

HI! this is my first post. I recently bought 2 aloe vera plants from Ikea and potted them in normal potting soil and kept it out in full sun . After a couple of days the leaves do not seem healthy. they have become dull and sort of soft and brown. I watered them once. Where did i go wrong?
Any advice is much appreciated.
Thanks
jaya

Did you read the posts immediately before yours?

Try giving it some shade. Don't water again 'til dry.

Also, "normal potting" soil is usually terrible for cacti and succulents because of its high peat content. If the soil is dark/black, it's got waaaay too much peat.

Plus, re-potting at this time might have stressed the plants.

And then watering a stressed plant just complicates the plant's recovery further.

Josh