Livery editor for GT6 was reeeeeealy plausible, i sense that they wanted something more for the so called "base models" i mean, they're maniacal in their work and i sense that they're working on a livery editor since the earliest GTIs there going to be more car customization options? Are you going to be able to swap the engine or put decals on the car?
"Both are technically possible, and we might be preparing it (laughs)."
I imagine Kaz is somewhat ambitious to have a livery editor in GT. Even though this interview was for GT6, he was at no point in denial of the feature. They might be preparing it... he says. I doubt very much it would make GT6, but it can and should be one of their objectives in GT7.
A livery editor has been mentioned numerous times in the past by PD in their showcases prior to GT5. It must be something they're working on right now. I'll be somewhat disappointed if a livery editor doesn't make GT7, especially as they've been prioritizing customization options in more recent GT6 updates. Think about it. Brake pad colours, in car dials, custom built rear wings and car numbers.
One can only assume that PD's next target in the customization department is a livery editor.... or roll cages... or engine swaps... but that's another story
(i like to think that the custom liveries present in GT2 were a first experiment, if they'd release a livery editor it'd be something really complex and developed in depth) btw we can only wait for the moment.