Stocking stitch doesn't care what kind of needles it was knit on it will still curl. You can carry up an end/ends on both sides instead, that will not be so uneven. I did one like that and really like the effect but that way it's probably better with only 2 colours and only 2 rows of each colour at a time.
You will need one DPN, the other needle can be straight or DPN or whatever. I hope I can explain this right:
Say it's red and blue. Imagine you have just knit 2 red rows and now it's time for the blue. The scarf is on the DPN.
Attach the blue on the end of the row OPPOSITE the end where the red is hanging off. You can knit from this end because it's a DPN.
So now you have the blue hanging off one end, hold the needle so that this blue end is toward your right side. The red is hanging off the other end toward your left side. Ignore the red: knit 2 rows with the blue (it's now back on the DPN). Knitting normally from left needle to right needle.
Now turn so the red end is on the right: blue is on the other end, ignore blue, knit 2 rows with red.
Did that make sense?