"That bird's breast is red."
Translation:그 새의 가슴이 빨개요.
Yep. Korean colors are a nightmare. 빨갛다 is the infinitive form. It becomes 빨개 when conjugating it. Yellow, black, and blue all follow the same form. 노랗다 -> 노래, 까맣다 ->까매, 파랗다 -> 파래. White is slightly different since it has the 야 instead of 아: 하얗다 -> 하얘.