Brother option1:
Wash it. clean it. use rubbing compound and polish it (you might not need any paint then). If yes, then go to any good paint shop. he might know the color code of your car or he gona check the exact color code under the hood. jaha chasis number hota hai . waha color code b lekha hota hai. for that little space charge you around 200 to 3, or 400 rupees.
Then apply that paint at home with cotton bud or ask the same guy if he is good at it. KALIM laga de apko neat kar k.
Option2:
If you go for the proper touchup as @smiling.tulips11 said. He might use sandpaper phir surface to equal karney putty b lagae ga color spray karney ga. and these dark and metallic colors spray hua pata b chalte hain and in some cases color match he nahi hota. dun know the reason why.
If I were you I go the option One.
Good luck!!