Bushings that come with the trucks will be 90a regardless of color.
I haven't found paint to affect grind at all.
As per what Indy say about their stock bushings, +1 for stock bushings regardless of colour are all 90 duro, but that is not to say that all bushings feel or perform the same, as some have felt a bit stiffer, some felt a bit more squishy, even though they still came up as the same duro with the gauge.
Had a lot of Indy trucks come through my hands, often the pro colourways or different colab versions with orange, white, black, burgundy red and other coloured bushings and skated most of them / feel them out on people's boards and they are very different to the after market bushings that you can buy, even the orange stock are different to the orange after market bushings, as others have said on here in the past too.
Also have all the after market bushings too and have them in boards for people to try, or to put on their own boards, and none of them feel the same as the stock bushings, which is interesting, to say the least.
In the past some people have often swapped out the stock bushings for others right away, as the stock bushings used to be pretty weird, but now they are pretty decent if you like medium to loose feeling trucks right from go. Stock bushings even from a few years ago felt way more firm than the current stock bushings now, so I think they have upgraded the bushing formula at some point, maybe when they went to 100% China production or something.
Different paint and other things don't matter to the feel of the truck, as the paint comes right off as soon as the truck comes in contact with anything that you grind or slide on, but it is more personal preference than anything. I know some people that will not touch a painted truck, not even painted baseplate, for whatever reason, so either factory paint or DIY paint jobs still skated the same to me.
* Sorry that was probably rambling a lot, but Indy are the main trucks I skate and have way too many boards with many different options, new and used, older and current stock.