I don't think I've ever seen the Wizard of Oz in color/colour! If I have, I don't remember - seeing it in B&W at the age of about 6 has stuck in my mind forever. I was absolutely TERRIFIED by the winged monkeys and demanded that my aunt turn the TV off! My aunt was babysitting me - my parents had gone out for the evening and she'd been so excited that the Wizard of Oz was on. If I recall, she wouldn't turn the TV off and suggested that I go out to the kitchen while the monkeys were on screen! I was not a very happy camper at that point. Scarred for life!
Anyway, one of my favorite funny movies is Four Weddings and a Funeral. I also loved A Fish Called Wanda. And just about all of the Monty Python movies.
When I was little, I thought "Those Magnificent Men in Their Flying Machines" was absolutely hysterical. I haven't seen it in eons - don't know if I'd still find it funny. A few years ago, I got the DVD of Peter Sellers' "The Party" - another movie I'd thought was hilarious when I was much younger and found it nowhere near as funny as I did when I was a kid. One's funny bone definitely changes over time.