You have to create the custom format.value error gone, i couldnt find that custom format so will stick with the long formula, can it be made to also check sheet 2 and sheet 3 same cell ranges, got a feeling it will be a long one, a big ask, but any help much appreciated.
Try it like this...formatting worked thanks, formula has a ref error, my work sheets are named "Page 1" "Page 2" and "Page 3" so i changed the "sheet" ref in your formula to "Page" and still got a ref error,