A picture would help a lot in gaining some suggestions. I don't fully understand what you are looking at, but I understand the concept of calming down busy blocks.
- sometimes a simple sashing in solid fabric between blocks is enough.
- making the same size/style block in a solid fabric and alternating them in the layout would be another option.
- if none of those suit you and you want to calm the block itself, as opposed to calming the whole quilt, you could see if taking a piece of contrasting piping to the top of the seams would break apart the fabrics and create some interest.
good luck. if all else fails, your cats will love it!