If you are talking about the veining of lighter and darker colors it's called Chlorosis. Here's a link on the AHS dictionary about it
http://www.daylilies.org/ahs_d... and here
http://www.daylilies.org/ahs_d...
It could just be because it is a dormant and just needs some sun to green it up or it could be the other problems mentioned in the above links.
I had one like that that had been in a pot for awhile and just needed some TLC with nutrients so I planted in one of the beds and added the usual alfalfa pellets, chicken litter, milorganite, slow release fertilizer plus I gave it some ironite and a little epson salt and it's just about back to normal. I did recently have a whole 4' x 30' bed of daylilies start to do this and the problem was the soil ph was way too high so the plants weren't getting any nutrients. The culprit to the high ph was the chciken litter that was added to the bed. I had added it at planting, but then went back a month or so later and topped dressed it. What I didn't realize at the time is the chicken litter had been changed from what I normally use; it had 10% calcium in it, which added to my already correct ph made it go way to high.
What I did to correct the problem was poured some water soluble Aluminum Sulfate ( the kind hydrangea growers use to blue up their plants) into the soil around each daylily at 1/2 strength so as not to lower the ph too much or fast and then I sprayed liquid chelated iron (with other nutrients) as a foliar spray to give the daylilies some quick nutrients. I plan to take a soil sample to our local extention office for a ph test (they will do the ph test for free here) to make sure it has been corrected.
Hope this helps