One of our Phoenix colleagues is rather well known for having to cover just about all his exposed skin. Long sleeve umpire shirts are just too hot and cost prohibitive for him, so he's allowed and encouraged to wear same-color / accent-color sleeves and balaclavas. He even has a black wide-brimmed bush / safari / jungle hat that he wears on the bases. Assigners and colleagues here all understand.
You know what looks passable? The 2016 MLB Panel -style shirt, with black or grey under-sleeves (black for black, sky blue, grey, or pink shirts; grey for grey or black shirts). Doesn't look that out of place. Even the 2010 Vertical stripe -style shirt doesn't look too bad.
Know what looks stupid as h3ll with under-sleeves?
Even if you get navy, or red, those red & white trim stripes just break up the arm. Then, most guys don't use navy under-sleeves, instead going for the cheaper, more available black... So Association Guys & Assigners!... how do you fix this? Modernize your shirts!
Hey, check it out... someone's actually making a 2016 Panel -style in Navy:
Would I wear that back in Wisconsin, or in any of the other navy-holdout states? Sure would... because while I wouldn't be thrilled to wear it, I'd at least delight in the knowledge that the clowns out there would have to buy at least one new shirt, too.
Which means, that while appreciated for supplying it to Ump-Attire for resale to us, the shirt, like sooooo many other things, isn't. made. for. us. yet.