In the past couple of years several teams have brought back a retro powder blue look. The sort of which were fairly common as road uniforms from the 1960s through the early 1990s and then just died out. The looks are coming back these days as an alternate jersey rather than a road jersey so they’re not true throwbacks, but they are certainly retro-inspired.
The Royals, if I remember correctly, were the first team to do it. Since then the Phillies and the Cardinals have joined in with nods to their old look. The Rays use a light blue too, though it’s not a throwback since they don’t have any “back” which to “throw.”
The latest team to don the downy-hued duds is the Minnesota Twins, who wore “baby blue” uniforms on the road from 1973 through 1986:
The 2020 alternate uniform, the club says, can be worn by the Twins either at home or on the road, but my guess is that you’ll see it at home more often.