There are a number of popular signs for "Colorado."
Two of them are mountain related. The other is a "play on words."
Since Colorado has lots
of mountains it is understandable how a sign would develop that
shows the ups and downs of a mountain.
In this version of the sign, you start with a "C" handshape on your
upper arm and you make a couple of arcs as you move down the arm
with your "C" hand.
COLORADO ("Mountain" version)
(Model: Byron Cantrell)
This next version of "Colorado" combines the signs "COLOR" and the
fingerspelling of the letters "D" and "O."
This is not some "joke" sign that isn't used by anyone. It is
actually a very common way of signing "Colorado." Part
of its popularity has to do with the fact that it is somewhat fun to
do a "play" on words. Another reason this sign is popular is because
it is easier to do a one handed sign than a two handed sign.