Such a warm and beautiful hat for winter, and perfect gift for Christmas!
Mosaic Knitting is so much easier than Fair-Isle, but looks very similar. You just have to work a few more rounds to show the same effect.
Once you get it rolling, this is a TV project!

I wrote the pattern with Picot Edge brim. But if you don’t want Picot Edge, or just want straight folded edge, replace Picot Edge row in the instruction with just a knit row.

Both Soavia and Silk Garden are Worsted Weight.
Mosaic Knitting pulls side to side, so that pattern gauge will come out smaller than it’s Stockinette Stitch gauge.

If you follow the instruction for the large hat with DK weight, it will come out to an Adult Medium on the smaller side.