This is what they look like.
This new duet has both of the sing a ma jigs in shades of blue. The big one is dark blue with the same ears as the feet of the blue sing a ma jig, green hair, a pink nose and a light blue mouth. He has the same hands as the royal blue duet, and the same feet as the dark blue duet. He holds a light blue teddy bear. He has the same ears as the little one from the 2nd pink duet, red hair, an orange nose and a dark green mouth. They sing "This old man, he played one" which would later be sung by the dark green sing a ma jig.
Here are their voices.
Big one: Dark purple
Little one: Red (Same harmony pitch as purple)
Sign on: Both: Hello (At the same time)
Song mode: Big one: Sing with us Little one: Song time!
Sign out: Big one: Bye for now! Little one: Bye bye!