I started the second week leting the seedling under direct sun-light, but comparing the photos of the 8th and the 10th day I apreciae that the leaves became brighter. Should I stop putong under direct sun-light?
Seedlings don't need a lot of light right out of the gate. A sunny window is just fine and will provide a bit of protection until she gets hardened up enough for full direct sunlight.
You could also try introducing her to the direct sunlight only in the hours of the day when the sun isn't as strong for a few hours at a time.
Hope this helps, happy growing! ✌️ 💜 🌱
Normally I would say plants are made for sunlight but if you get yellow leaves than I would recommend some grow nutrition if you used no pre-fertilized soil. But to be safe put her outside but with times of shadow over the hottest time, about 11am to 3pm.