Yes, the females are brownish red; the males are almost white bordering on pale blue. The other give-away is the 'slab sided' head, appears very flat around the eyes, as in a barn owl. Also a rather 'erratic' flight pattern, similar to a lap wing. The long 'swept back' wings appear to be disproportionately slender.
Ian Roberts, Bowland FR
PS Your local constabulary should have an appointed Wild Life Protection Officer ( usually a local village 'bobby'), get the information of your sighting to him/her.