Pronounced as one letter, And written with three, Two letters there are, And two only in me. I'm double, I'm single, I'm black, blue, and gray, I'm read from both ends, And the same either way. What am I?

Why this works

This riddle cleverly plays with the word "eye." First, it's pronounced like the letter "I," but it has three letters: E, Y, and E. The riddle mentions “two letters there are,” referring to the two letters E and Y, while “two only in me” hints at the two E's in the spelling. The line "I'm double, I'm single" suggests that an eye can be one (single) or two (double) when you have both eyes. Additionally, eyes can be described using colors like black, blue, and gray. Finally, "read from both ends, and the same either way" indicates that "eye" is a palindrome, as it reads the same forwards and backwards. This multifaceted description makes "eye" the perfect answer!