What brand is sold at the dealer? Is it Duplicolor? You can buy it in Walmart or pre-order at Pepboys. Magnetic gray is hard to find.
If the scratch is not noticeable in 3-5 ft distance, I'll just leave it...really. Like JCA21 said just wax it and buff for now. If the scratches are worse, then have the pros do it. I have tried touch-up paint plus clear coat, the white and silver is a closer match to the color of my vehicle, but the galactic gray in the 4Runner is very different. Oh..yours is a $40K vehicle I am afraid a 6 bucks paint will make it look worse..one of my car have pimples..LOL! because of the chips applied with touch up paint and clear coat, my vacant time is only at night so I didn't know how it look during the day.