I just found out I'm colorblind.

The humor in this one-liner is a clever play on words, specifically an idiom. The setup reveals the speaker is colorblind, and the punchline, "The news came completely out of the purple," is a twist on the common phrase "out of the blue." "Out of the blue" means something happened unexpectedly or without warning. By substituting "purple" for "blue," the joke highlights the speaker's colorblindness while simultaneously making a silly, unexpected change to a well-known expression. It's a classic example of linguistic misdirection (Review) used for comedic effect.

Colorblindness, or color vision deficiency, is a condition where a person has difficulty distinguishing between certain colors. It's not about seeing the world in black and white, but rather about a reduced ability to see color differences. The most common forms involve difficulty distinguishing between shades of red and green, though other types exist. This generally genetic condition, more common in men, provides the perfect backdrop for the joke to playfully suggest a world where even idioms might need a color-corrected update.