We have very similar tastes in fabrics and colours and I think it took us two seconds to decide on making a super scrappy rainbow Supernova! Each block will also have a different low volume background. I used the quilt design tool to do a mock up of various rainbow themed blocks to help us decide on how our layout would work and we settled on one that has five different colours in each block.
There are 12 colours in our rainbow: Red, Pink, Peach, Orange, Yellow, Citron, Green, Aqua (or teal), Blue, Indigo, Violet, (radiant) Orchid
The swap is scheduled for 10 blocks, but we're going to do 12 so we can have a bigger layout (4x3 instead of 3x3 and one on the back). The first month we're making each other two blocks.
I found the original instructions on Freshly Pieced a little confusing for cutting because it's for cutting in bulk. These Supernovas have specific fabric placements and different fabrics for each block background, so I made a little tutorial to work along side the original to explain how much cutting is needed for one block and which pieces to cut and sew so they work in specific placements; including a short cut!!
The original tutorial is linked below, but my tips and tricks are here