Yellowish sprouts... Problem or not?

I wouldn't worry about the color - SORT OF... I see a couple of problems with your grow that have me concerned, though... First is that you've chosen Miracle Grow soil as your medium which is providing your seedlings with nutes they don't need and don't want and will continue to do that during the whole grow since it feeds for several months. You need to choose a different medium (I use ProMix myself) and a nute line up so YOU can decide what nutes the plant gets and WHEN it gets it. The second problem I see is the size of your pots. Autoflowers really desperately hate to be transplanted - transplantation stresses plants and this interrupts the pre-programmed cycle built into autos. They need to be germinated in the size pot they're going to finish in! Here's what I would do if this were my grow: I'd pick up some 3-gallon fabric pots and some different medium - and because I use it myself, I'll recommend ProMix. Then I would VERY CAREFULLY transplant the seedlings into them leaving as much of the Miracle Grow behind as necessary but not so much that the roots are free... you'll find your seedlings have developed fairly long tap roots so don't do this in such a way as to break them! I'd then give the plants a good soaking with PH'd water and let them rest. When they're about 3 weeks old, you can start introducing the nutes you've chosen but only at 1/4 strength... if they tolerate those well enough, you can increase to 1/2 strength, etc... Good luck, mate!

Hey mate! Your seedlings look good 👍 don't worry. Its normal they will get a little lighter once the roots expand troughout the whole medium (that is not very big) and use up most of the nutrients avaliable in the soil. That doesn't mean your soil is not good. I'm sure when the point comes you are gonna transplant them into bigger pot 's with fresh soil (can be same brand as you used before) the seedlings will pick up colour again and get a little darker. Good luck 🍀 ✌️