...I did manage to get the colour changed . It was originally described as 'white' and has now been altered to 'cream' but, again, they refused to acknowledge "Royal Ivory"!
Mine is "cream" too, which has always slightly irritated me. The rest of the V5C is correct though. All Austin 7s were originally documented with an 858cc engine, the size of the Mk1 Mini, rather than the 750cc actually under the bonnet.
If you've restored or imported a vehicle the process to get it registered with authentic information is quite involved, rightly so. Once you have a V5C it seems the DVLA's only concern is matching a registration number to an owner.