My Greek boy is nearly 7 years old now, have noticed recently that the top of his shell seems to have started to turn more yellow, it is just discoloration at this point, there is no obvious damage or softness to the shell. He had some old issues with some rot and very minor shell deformation from bad husbandry before we rescued him (4 years ago) but he hasn’t had any issues since I’ve had him. He gets appropriate greens twice daily and is under a Mercury Vapour bulb and gets calcium and D3 every few days. I’ll try to get some pics up shortly but I’m worried this might be MBD or some kind of rot. I haven’t been able to find anything online specifically referring to what I’m seeing so not sure if it could be normal? I’m looking forward to any info possible.