So..... Lost Carcosa has a Yellow and Purple symbol on my game board. I don't have any purple mythos cards. I have seen Lost Carcossa events on Blue cards though. Is my board a misprint? Is it supposed to be blue?

Lost Carcosa should be yellow and blue. I recommend reading the F.A.Q. which you can find in the Arkham Horror support section, where this and other questions are answered.

Many thanks. You are a gentleman and a scholar

Until I read the Faq I had been playing it used Red and Blue and Yellow cards. 'Cause, y'know, purple = red + blue. Then I realized there were no Red Lost Carcosa specifics.

Kingsport's Underworld got the same purple dot. I'm pretty sure that's why FFG left Other Worlds out of Innsmouth: "NO! No more miscolorings! Ever again!"

I like the miscolorings. I've never been diagnosed as colorblind but I can hardly tell the green from the blue on the main board. I heard once that's way FFG deliberately changed the color on the expansion boards.