Thanks so much! Your reply was such a relief for me! But the strange thing is that discoloration appears in spots and are on some lilies. 3 in fact. And others (same silk road and conca d'or) are growing like 30 cm from them and their leaves looks fine, without any discoloration. Also is that normal that a couple of outer scales of the bulb was rotted?

Soil conditions can change just a matter of inches away so it is not overly surprising that some are showing discoloration while others are not. And older scales can rot away. As long as you are sure drainage is very good and watering is not excessive, I wouldn't be concerned.

Thank you so much! The drainage is perfect. The soil is super sandy, and even after heavy rain tomorrow it's like a desert. I know that these purplish borders around leaves are normal, but that dots really bothered me. Now I'm not that concerned. Maybe you could advice which element I should add in to the soil to eliminate these dots or don't let them multiple? Also it's the forst year of these lilies after transplant so maybe next year they wont be showing? Thanks in advance!

some of mine have that, im not worried by it...