Every Single Thing In the Worl=4!

[Blue]

eye is too easy,its not math,sneaky figured it,just count the letters :)

[Pink Floyd]

Every word works...
Let's say you completely disregard how many letters are in the name.
1 letter - (One > Three > Five > Five has 4 letters)
2 letters - (Two > Three > Five > Five has 4 letters)
3 letters - (Three > Five > Five has 4 letters)
4 letters - (Same principle as 2)
5 letters - (Four)
6 letters - (Same principle as 3 or 2)
Ect..