There's already a hole in my knitting

I've been getting ready to start a very special project over the last week, and haven't had quite enough time before bed to knit. Last night though, for just a few hours, I finally found the time to start said project, and I have discovered that I am a crazy person. I have decided to make an infinity scarf in the round and then seamed together at the end (like a tube joined at either end) out of fingering weight yarn. Yes. Fingering. Why? Why would I do this to myself? I blame the lovely colors of Madelinetosh Tosh Merino Light, honestly. Who couldn't fall in love with those colors, and how squishy soft they are immediately? If some of you readers are saying me me, then I applaud your self-control. Because I am not that person. As soon as I got the idea in my head I immediately ran with it, and of course bought an obscene amount of yarn (no regrets).

This is also a pattern of my own devising, so it's going to be an interesting journey from start to finish. There's colorwork sections that are just blocks of color, and I thought that I could just fudge around it and do stranded colorwork. (I was wrong. Very, very wrong.) So now I have a sample knit with a large hole in it, and it might be a little bit too big in the gauge section as of yet. I'm knitting on size four needles right now, but I think that I might bump down and try size three tonight after I make my way home. However, I love the colors that I chose for each part of the scarf, and am really excited to work them in with the grey (the main color that I'm using is the Astrid Grey from this post!). Before I can work them into the grey, I have to figure out what method of multiple color knitting I'll use to put them in. I'm thinking that duplicate stitch will work the best, since it's in the round, and the swathes of color aren't all that large. (Most of them are just a few rows across.) I've decided that I'm not going to post a picture of said special project just yet...I want to get my design more finalized and work out at least some of the kinks before I do. However, if you have any methods on how to insert colorwork seamlessly into the round without creating holes, then please let me know down below! I'd love to have any advice!