The key is in D major which means your do will be D (first space under the staff) I will give you the first measure:
Do Do Re Mi
I'd say A. Since Color Values go along with RGB
Answer:
TAB shows which frets to play on which string.
Explanation:
TAB is usually easier to read than regular scales and notes. It shows the specific fret you play on the specific string instead of the clef and note.
Tab usually is for guitar and is has 6 lines denoted for the strings of the guitar. Instead notes, you would see the number of the fret you are supposed to play on.
Attached is a TAB I made for a specific song.