Baby Poop Color

My 18-day-old baby boy is mixedly fed (breastmilk & formula). Initially, his formula milk was Nan 1 Optipro. But then our pedia had changed his formula milk to Nan Comfort due to colic. When my baby was on Nan Optipro, his poop was bright yellow. But when we switched to Nan Comfort, his poop was not as bright yellow as before (see photo - it has now become lighter). Is the color of his poop normal?