When they finally started making them in denim a couple years ago, I got two pairs, one light blue and the other darker blue, and now that they FINALLY started showing some wear (see footnote), I purchased two more pairs, this time in a darker color.
Care instructions said to wash separately and in cold water the first time, because they are so heavily dyed, they could bleed. I washed them with my pillows, and had no issues with bleeding. However, after multiple wearings and washings, they STILL have that new smell. It gets annoying after a while.
Footnote: One of my cats jumped off my lap, and left a half-inch tear in the lighter-colored pair, which I sewed up and you can barely tell it’s been mended.
(Their clothing is expensive, but SOOOOOOOO worth it because it’s so well made.)