What are you trying to accomplish here, do you plan on respraying, or just doing the best touchup you can?
If the plan was respraying, I wouldn't mess around with trying to blend the clear on a part as small as a fender, and would feather out the chip, wetsand the rest of the fender with 800 and hit the feather with a little epoxy. Next day sand you epoxy spot smooth, spray base till coverage and have a good blend in the area, followed by clearing the rest of the fender. You could probably pull off a pretty sucessfull clear blend and backtape it off on that sharp bodyline on the fender and not reclear the whole thing, but really once your that far, why mess around with backtaping and blending the clear, and not just do the little bit extra sanding and clearing?
Seeing you painted this quite awhile ago and used an activated base, I don't think lifting would be quite as much of a concern as otherwise, but still would spot the featheredge with a little epoxy for insurance, and in case you don't have a perfect featheredge or happened to leave a small divit that would show up after its been painted.
If you planned to touch up with a brush, then you could possilbly get it looking decent by dropping in some activated clear so the level is above the existing clear, and wetsanding it level and then buffing, but likely still see it when you look close. Maybe you won't be happy with it, but really wouldn't take that much to attempt, and if your not happy with it then you could then spray it instead.
If you do happen to need to drop color and its a metallic, it will often be darker if its applied with a brush, then what was sprayed, due to how the metallic settles (sounds like you said you still had color underneath). If you need color in the chip and its a metallic, I'd probably mask around it, spray a little color into the chip. Wetsand off any base overspray around the chip, then drop in your activated clear so the level is above the existing clear. Next day wetsand it level, using a paint stick to back up your paper, and then buff the spot.
If you still have color in the chip, which sounds like is your case. I'd drop in some activated clear with a brush, and then next day level an buff like above.