Common Letters

Three people (A, B, C) are each given two colors, for a total of six colors (blue, green, orange, purple, red, and yellow.) In comparing the colors they received, B makes the following observation:

"The number of common letters between my two colors is one less than the number of A's common letters and one more than the number of C's common letters."

Find the colors each person received. Is there more than one answer?

(For this discussion, dual letters are only counted once. For example, yellow and purple have only two common letters: e and l.)

Source: Original.


Solution
Mail to Ken