Aww jangan risau, memang macam tu je normal untuk baby on formula! Warna kuning kehijau-hijauan atau brownish tu semua okay, kesian first-time mummy stress je hehe. Yang penting baby poop consistently (not random colours jumping everywhere), besar sikit, and baby happy makan and tidur, tu signs okay je. Kalau ada mucus berlebihan, tiba-tiba jadi very loose/water-like, atau baby nampak uncomfortable and not gaining weight, then boleh check dengan doctor; but sounds like you're doing great!