Yay!!! I never get riddles right! Now I will have to revise that statement and say "sometimes" I get riddles right. Now I get to write one. Hmmmm . . . .

<font color="blue"> 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 grey.
I'm red from both ends
And the same either way.
What am I? </font>