sir instead of being worried for color match paint area please focus over the deteriorating metal under the color at all such points. its not just that few inches causing rust boil it will be whole full patch of min 6 x 6 or 2 x 8 inches which need rework & finishing. surgically these boils seems to appear over mig-joining point. only an old school denter can carefully remove rust, work upon such sections without messing up the shape & joint integrity. Painter can handle it for finishing only.
