In my opinion, if your Mitsio has any blue, it's probably a cross.
I love Mitsios and I have 4 males and 3 females (pics are on my profile in two albums - one called Pete and one called Mitsios - for anyone who wants to take a look and judge)... Mitsios do sometimes have red "U" bars and reddish/brown markings, but I have never seen a pure Mitsio with significant blue on it... other people will tell you otherwise and claim they do have blue, and they may be right, but in my experience blue = bad when you're dealing with Mitsios.
Another good way to judge is to check them when they're sleeping... almost all male mitsios will start to fire up yellow when they're asleep (especially on the stomach and throat)... if the blue comes through more when they are asleep, then you've likely got some form of cross...
And no, I'm not looking for a debate... I'm just sharing my personal observation on the matter.