Elf Sternberg

I can think of to examples in movies. The Wizard of Oz and A Matter of Life or Death, released in the USA as Stairway to Heaven. I think the latter might be a more direct influence on the concept, since it is, in part, a romance, and the coloured world is where the romance can be.

Of course, there's other Japanese influences, and a Doctor Who story last year used the alien medical mistakes idea. At least it doesn't involve humorous accidents with buckets of water.