leaves getting yellowish sections also when should replant?(pics)

plants are just less than a week old, the first one sprouted last friday, havent checked the ph level and the pots are about 3.5 inches wide and just under 4 inches tall the tallest seedling is 4 inches tall and the shortest one is about 2". when should they be replanted to bigger pots? also some of the leaves started to get lighter green-yellowish spots. whats wrong with them?

what kinda light ya using? could be heat...