Originally Posted by: dreampage 
It's because the lighting model is adjusted for HDR displays. If you don't have an HDR screen you can't see the full spectrum of the picture. Not enough brightness in the sunshine and not enough details in the dark. I agree that on regular screens the game can look dark and washed out, especially in cloudy weather. The track surface and the environment can be surprisingly dark even if it's midday but cloudy. You need an HDR display to fully appreciate the graphics.
I would have to correct you here - this is a lighting bug that has carried over from FH3.
For example, you'd be driving certain cars around certain times of day, and from the cockpit view it would get very dark or very bright, but the moment you switch to one of the outside views, colors, contrast and brightness displays correctly. However, when you're driving a car that's relatively dark from the hood view, you'd again get this problem, but it remedies itself once the dark paintjob is out of the way.
I did plenty of experimentation with this in H3 - it's a lighting bug, nothing more. You might look at it as a bit of an oversight. I'd suggest everyone to stick to the full screen/bonnet cam or chase cam. Besides, it only happens on certain tracks around certain times of day and not every car. Depends on what internal contrast level is set in the car's cockpit.
Horizon 3 is not a game that's natively made in HDR, in fact, HDR is an enhancement, a graphical add on so to speak.
Guys, please take the liberty of reporting visual bugs here:
https://forums.forzamoto...hical-glitches-here.aspx