Alphablock U is seen without glasses in this episode.
STORY: Alphablock E is build a car when alphablock U comes along and clumps with E. They make the sounds "OO" and "U". When B and L came along, they made the word B-L-UE blue and blue paint showed up so UE can paint the car blue. UE hops into their blue car and takes it for a spin and as they do it, they see 2 Bs, AR, E and C.
To find out more about the word, go here.