Well the color is from reflection to the lighting. But the reason for that area to reflect is that the metal is curving on that area. How could this happen. Well if you just think on what you see on the coin, thinking about the die is the easier explanation. When a die is polished, the fields are the affected areas.The field is the outside of the die. The devices/design is in varying levels into the die. The die is just the opposite of the coin. Where the coin is raised, the die is incuse. So when I polishing happens, if the edges of the outside field area is reduced near a device, it removes a little more metal from that edge. So when it removes even the edge of a device, the coin will show a raised area next to the device. The polishing is weakening the fresh squared edge, when the polisher dips into the opening of the device. The worker does not see this happening, but it shows up on the coins struck by that die. That is what you are seeing on your coin. Remember, when looking for a doubled die, look at the centers of the devices, on on the outside edges. Die abrasion, die polishing scratches and
Machine Doubling can make it look like something there. But on a doubled die you will see the devices enlarged in the center of the devices. Look for the spread or now on the single squeeze dies, the next term I'm using is distortion of the devices. But the locations of the DDRs are not on the outside edges of devices. About this time the single squeeze dies started. The
DDR is in a total opposite area on these on the dimes. The are more towards the centers of the designs.


So look in the areas where known DDRs are found. The new dies are showing doubled dies in a different area. Also on the obverses of dimes, they are very few.
http://www.varietyvista.com/07%20Ro...Listings.htmCheck out the link to see what years to look for on the
DDO on dimes. This will surprise you. You will stop looking at obverses. 1989-P is the last one listed on V.V. Wexler lists just one that is a big deal, but not many know about this one:


So not much going on with dimes, except for the 1999- present on the reverses. The rest of these looking at these is a waste of time. But someone may find a new die, if you are looking in the right areas, and not on the areas that were popular years ago. Look in the central areas of the designs for a new listing. (Same on dimes and quarters) The target areas is the same, in the centers.