[meford4u]

It could be one of two things that made the colour different.

Actually, it's more than two factors.

First, you may not have put on enough costs to cover the door handle properly. And if you didn't prime it first, that may be the case.

Second, paint will fade over time from the sun and outside elements. So getting an exact match would be near impossible, even for a body shop.

Also, metallic paints tend to go darker if you apply to heavy of a coat. It may not run on you, but it will appear heavier in some spots and lighter in others. We call this modeling. That seems to be the case with what you have done. A final very light coat would have fixed this issue.

Another suggestion I might make is once you have applied the primer, put on a coat of clearcoat before you start appling the base coat. You will get better adhesion and a shinier finish.