Madelyn suggested a while back using waffle weave with different colours to produce different colour floats on each side, and the opposite colour in the middle. I didn't do it for the project I was planning at the time, but have since used the idea for baby towels. I will put some photos in the gallery. Thanks to Madelyn for the suggestion!
It's a 6-shaft draft, with 7 treadles plus 2 plain weave treadles. The colours are threaded 3 peach ends, 2 butter, 3 blue, 2 butter, in a 10-end repeat, then the weft follows the same pattern, so that one side comes out with peach float squares and the other with blue, then the squares have the opposite colour showing in the middle.
The floats were very long though and it seemed a bit impractical, so I rethreaded all the treadles so there is a double row of tie down stitches, reducing the length of all the floats. I've now woven a second towel with butter-coloured weft only, the reverse side will show slightly more blue than peach with the overall butter background.
I'm planning to do some cotton and linen waffle tea towels next, but want to use a range of colours, so I think I will use an off-white cotton warp and different linen colours in the weft. As stripes usually look better lengthways I might have to do a wider warp, so that I will weave the towels sideways and the weft will be along the length of each towel. If I can bear to wind and thread up a wide warp 30 epi!
I love the photos you posted in the gallery, they look great! Thanks for sharing, I'm excited to see what you come up with next!