@Mach_Tuck: I added an "Optimistic" vote. Even if Kia won't repaint everything under the SB, they surely will under warranty. There is no way on earth that a repaint will return crappy bumpers still untouched! There is no way that Kia will expect you to take twice as long to get your car finished: which is what would occur if the bumpers had to repainted subsequent to the metal panels being painted!? The only issue I see with any of these decisions is if Kia insists that the front bumper damage is from road debris. If you clearly document that most or all of it cannot be road debris, then it has to be covered under warranty.
From page 14 in the warranty manual
https://www.kia.com/us/k3/content/media/all/warranty/2018_warranty.pdf
2. What is Not Covered • Any perforation due to corrosion of the Kia Vehicle which is caused by industrial fallout, accident, damage, abuse, vehicle modifications or damaging or corrosive cargo in the Kia Vehicle. • Any surface corrosion of the Kia Vehicle which does not result in perforation, such as that caused typically by sand, salt, hail or stones.
• Any perforation due to corrosion of a part of the Kia Vehicle which is not a body sheet metal panel. As used herein, “body sheet metal panel” specifically excludes all parts which are components of the exhaust system of the Kia Vehicle. • Defects or damage resulting from the use of parts not sold or approved by Kia including the resultant damage to associated parts or systems. • Any perforation due to corrosion of the Kia Vehicle caused in whole or in part by a failure to maintain the Kia Vehicle in accordance with the procedures specified in paragraph 3. “Your Responsibilities”
Obviously, bumpers are not "corroded" in just a few months of the first year. And picture evidence taken by a dealer will be accepted by Kia as proof of not being caused by "stones", etc. In bold, we have a possible "out" for Kia, but I am counting on not this early! Chipping/flaking paint is not due to any corrosion. Nor has enough time elapsed to result in the amount of damage seen due to stones/debris; not on this many cars. They've admitted as much with the Yellows. And all other colors exhibiting identical characteristics must be treated as non corrosive damage due to paint failure, i.e the warranty must cover it.