This is a variation on the traditional Norwegian Selbu mitten. There are a number of different intarsia patterns used in this region. Usually combined to your own taste.

The ribbed cuff is usually knitted with a few thin stripes of the pattern color. I’ve elected to skip the additional 1-2 patterns common at the wrist.
It’s also common to skip the ribbed knitting and add 2-3 different patterns at the cuff instead.

The front of the thumb usually carries a variation of the front mitten pattern. In this instance I’ve continued the pattern of the inside of the hand on both sides of the thumb.

The most common color combination is natural white and natural black (charcoal). Other known color variations in traditional Norwegian mittens are : red and white and red and black.

I strongly recommend knitting a small sample to see if you need to shorten or lengthen the pattern.

The pattern is charted with some written instructions.

ALTERATIONS
If you want to scale the mitten size up or down:
Up : use a larger sized needle or add to the beginning or sides of the intarsia pattern.
Down : use a smaller sized needle or cut off the pattern at the sides or at the beginning of the intarsia pattern.