I bought this cactus which I think is a lophophore W caespitosa (correct me if I'm wrong) some week ago and I
can see that it's a bit yellow and cracked here and there.
It's also quite pale
Mites?
Can anyone identify the problem?
imPsimon attached the following image(s):

IMG_1453.JPG
(1,411kb) downloaded 95 time(s).
IMG_1454.JPG
(1,668kb) downloaded 93 time(s).
IMG_1457.JPG
(1,419kb) downloaded 93 time(s).
IMG_1458.JPG
(1,469kb) downloaded 96 time(s).