Alah don't worry, warna tu memang normal je untuk baby yang minum formula more, biasanya lebih kuning atau coklat sikit compared to purely breastfed babies, so that's perfectly okay! Since perut dia lembut, dia tak nangis, dan dia berjaya berak bila you massaged, it sounds like constipation biasa ja, bukan something serious, tapi kalau dia consistently tak berak lebih dari 3-4 hari atau perut keras/buncit, better check with your paediatrician cepat-cepat ye, just to be on the safe side. You're doing great already with the massage and cycling movements, tapi do make sure dia minum cukup air sikit if possible, especially since more formula. Take care, mama!