Well, in my experience it could mean that either you have a specie with a tendency to have that color of leaf of you have it in a high light situation. Probably both. he problem with the average crypt bought at a lfs is that they are often C. wndtii. I seems that wendtii has becoem a catch all or rather there are so many varieties or palnt that are all basically hte same that it is hard ot tell the difference. Often the appearance of these plants, as wiht many types of plants, is based largely on their enviroment.
I would not worry to much. if their is a problem, crypts tend to melt so fast that you will know tomorrow. The leaves deteriorate expreemly quickly when they die. Is this a new aquisition or one you haev had for a while? Often new plants will melt a bit, due to the change of enviroment, but generally they will come back.
Does it look like this? Please excuse the gravel, its Carolyn's tank. It is under 1.6 wpg of t5 florescent (5.5 gallon) there are no ferts arred to the tank but I am sure that NO3 gets high. Same wiht P. Ironically, there is no algae. This is a wendtii but it seems to have this nice rust brown color. I really like this one. I notice that some of the wndtiis in my tank are starting ot turn back to this color. I know they got stunted for a while when I had an algae battle, redid my lighting and moved them around. The color starts at where the stem meats the leaf and slowly works its way to the tip. In my tank that is with 3 wpg and most ferts.
It is a little hard to tell but are he bigger, older leaves dying. If so then it is jsut melting. Nothing to wory about because the new small green leaves at the bottom prove it is still alive. there are two things you could do to help it more though. One, once you palce it don't move it. It takes crypts a while to adjust to their surroundings and every time you move themit sets them back a bit. Two, make sure its feet are well fertalized. If you are using a plant gravel liek eco or flourite then it should be fine. If not hen you could add a root tab with iron, or part of a root tab below the roots of the plant. This alsomakes it important not to move it. I would try the seachem root tabs. I don't really go for the whole jobes sticks and things. They can work good, but do you really want o experiment righ tnow? Also, a slow release root tablet would be best for use in your larger size gravel. Less of the fert would get into the water column that way.
Just thought I would post an update. All the wendtii is doing great! All of the new leaves are dark bronze color. There is one or two old leaves that are still green, but the plant is growing well and healthy looking. I guess it must be wendtii bronze or something.
But I jsut saw some wendtii considered to be bronze in an display tank. They looked really nice but the store didn't offer them in their for sell tank. If I was to find wendtii var bronze...is it something i should keep and why are the leaves on the bronze soo much lighter colored(in bronze ofcourse) then the picture in the above post?