Thanks so much for all your votes and suggestions :-)
I hope you won't think me rude for not replying until now, but my phone decided it wouldn't let me post replies and my computer gave up on me a few weeks back! I finally have my new computer so can get back on here properly :-D
In the end I went with a red frame and blue sashing, because it was the best of both worlds and solved all the issues I had with trying to choose between them! Such a simple solution, but without this board I'd probably still be thinking "Red or Blue?", instead of it being mostly quilted!
I'll try and get a photo up tomorrow once I've found my way around Windows 10 a bit more!
Thanks again everyone :-D