Using Lakes cast on 32 sts and divide them across four needles, 8 sts each. Work two-colour brioche. The beginning of round is between needles I and IV. Start with Lakes as colour 1 and White as colour 2.
When the cuff measures 2,5 cm, join Sauna as colour 2. Work until the cuff measures 9 cm.
On the next round *knit together the yo and next st, k1*, repeat *–* to end of round using Lakes. Increase 8 sts: *k4, increase 1 st (knit the strand of yarn between the sts through the back loop*, repeat *–* to end of round = 40 sts.
Begin the colourwork pattern on row 1 of the chart. Repeat the 8 st pattern 5 times. Now keep repeating rows 2–15 of the chart.
Note: When the piece measures 4,5 cm from the cuff, mark the spot for the afterthought thumb: work the 10 sts on needle I and the first st on needle II. Work the next 8 sts using a different-coloured yarn. Move the 8 sts back to the left-hand needle and work to end of round following the chart.
When the piece measures 12 cm from the thumb or when the mitten covers your little finger, begin top decreases: at the beginning of needles I and II k1, skp using Lakes; at the end of needles II and IV k2tog, k1 using Lakes. With the remaining sts work following the chart. Work the decreases on every round until 8 sts remain.
Break the yarns and pull them through the sts. Securely weave in.
Knit like left mitten but make the thumb hole with the middle 8 sts on needle III.
Remove the different-coloured yarn. Pick up the sts from both edges of the thumb hole. Pick up additional sts from both sides for 19 sts in total. Divide the sts onto three needles and work stockinette st in the round using Lakes.
When you have worked for 5 cm or when the mitten covers half your thumbnail, work the top decreases: k2tog at the end of each needle until 4 sts remain. Then k1 and pass the other sts over from left to right. Break yarn and securely weave in.
Steam the mittens lightly.