Why do we think they’re in colour? These were shown in theatres?

http://au.truveo.com/Bushells-Tea-Advertisement-The-World-of-the-Future/id/3468912703

seems so … thanks google!
[and all I searched for was Bushell's Tea]

Have never seen the Bushell’s commercial before but the Aeroplane Jelly ones are very famous. They were made by Eric Porter who made Bimbo’s Auto for Columbia in the 40s, and our first animated feature Marco Polo Junior Versus the Red Dragon.
You can see more of his work here. http://australianscreen.com.au/company/Eric+Porter+Productions/

Wonder what Tasmanian Raspberry tastes like…

(freeze frame quickly at 0:21 on the 1959 ad)

Why do the voices all have English accents, and not Australian?

S porridge - it tastes terrific.

Bill the Plut - because it was a very long time because it was considered acceptable to have a straight Australian accent in the Australian media.
As it happens, if you know what to listen for you can hear they’re not English entirely - the accent isn’t strong.

Haha, every line of dialogue in the last Aeroplane jelly commercial is pure comedy!

I love how the first commercial changes from a quasi-serious documentary to pure cartoon with the car of the future.

“And every Aeroplane Jelly gives you glucose.”

Comedy gold indeed.

Jerry, “jelly” here is the same as “Jello” to you Americans. Not like jelly as in jam or jellies as in soft candies. “Jellies as the plural there is a bit confusing I admit! The Aeroplane (not Airplane as you’d say) Jelly jingle is about the best-known and longest lasting Aussie ad jingle, second only to “We’re happy little Vegemites/Puts a rose in every cheek” Vegemite jingle.

I was actually contacted a few years back about a redesign and styleguide for Bertie but unfortunately I don’t think they take the brand seriously any more. I would pretty much have been doing it for free. Too bad, as old Bertie had charm and warmth.

And Bill, just to add to Elliot’s comment, if you look at your own American media, this was no different at all to the clipped, quasi-English accents of Golden Hollywood - Think of Katherine Hepburn, Bette Davis or even arguably Cary Grant or Errol Flynn (yes those ones are obvious curve-balls due to their origins but I use them to illustrate the point). I think animation fans have a slightly distorted view as we’re so used to the bronx and New-Joisey-type accents. I think this ‘clipped accent’ thing is also why The African Queen had such an enormous effect at the time which would not be as obvious to our ears all these years later. Even allowing that it came in the middle of the Noir period. And being a Coen Bros fan I loved how Paul Newman and Jennifer Jason Leigh played on those quasi-American/English accents in The Hudsucker Proxy!