Sorted. :biggrin:
1) In the iCUE Settings tab, I selected my K95 device and clicked 'Clear Onboard Storage' next to Device Memory. On my next reboot my K95 was RED with a WHITE top strip instead of the Rainbow.
When I now clicked into the Onboard Profiles tab, all three slots showed 'Empty'.
2) As they hadn't been working, I deleted my old Hardware Profiles, (which no longer had the '1', '2' and '3' next to them) and the folder they resided in. (Maybe they might have worked again if I tried to upload them into the now 'Empty' slots :thinking:)
3) I created a New Folder for my Hardware Profiles, and created new Hardware Profiles, (selecting the Hardware radio button).
4) In the Onboard Profiles tab, I was able to upload these and this time I saw the progress bar update as the profile copied across, which it wasn't previously doing before blowing everything away and starting over.
TLDR - Blow everything away and start over :bomb: