For color adjectives which end in -ㅎ, special conjugation rules apply.
Why is " The yellow house is expensive" is wrong?
because the subject is yellow. the expensive is adjective to the house
isnt 노래 song?
노래 = song
노래이다 conjugates to 노래예요: "is a song"
노랗다 conjugates to 노래요: "is yellow"