That's a pretty large surface for using just touch up paint. The results are not going to look good.
Another option is to locate an automotive paint supply store. Use Google to locate one in your area. Most of these paint shops can prepare a spray can for you. They have a small hand held device (plastic or glass) that the paint is poured into, then an aerosol can is screwed onto this device, and you spray the paint on as if it was a spray can.
The results are much better than trying to use a touch up bottle. The cost of the device is more, but it can be reused forever. You only will need to buy cans of aerosol.
The link below is an example of the device I'm refering to. You could buy this, then buy the paint only from a local automotive paint shop: