Trust me I've seen enough dropkicks come through the doors at the panelbeaters to know why someone resprays their cars or changes head and turbo.
NO ONE resprays their car for the hell of it in the same colour it was before. They only ever respray the car in the same colour to cover up something or to fix damage.
If you're lucky, it's cos of faded paint. Worst case scenario its cos it had a frontal, or was a VIV car, or a rebirth. You're just as big a dropkick if you're naive enough to believe the in the kindness of the human spirit when it comes to used car sales. If you believe the worst it makes the seller work harder to sell the car to you, or at least be more willing to drop the price. Don't delude yourself and buy a car with glazed over eyes.