Although Clearcoat may discolor over many years there is another problem when the paint you apply is an off color or yellow in comparison to the rest of the vehicle.
You will be left with a mismatch job that looks tinted when compared to the adjacent panel and yellow in hue.
The reason that this happens is due to either contaminated or improperly mixed clearcoat or technician error.
If the problem is the mixture of the paint it could be due to contaminated products or the wrong hardener or activator.
If the problem is due to technician error it …

When vehicle manufacturers changed over from glass headlights which were often just large bulbs held in a bezel back in the 80’s it gave them the opportunity to introduce a variety of different tear drop shapes that better matched the low drag coefficient shapes on front bumpers.
Recently a friend told me of a problem he had when painting a motorcycle gasoline tank.
Most new vehicles in the past 15 years use a two stage paint system that starts off with a flat base coat and adds a top clear coat for gloss and durability however not every car needs to use a Clear Coat for good results.