Toyota sells small bottles of touch-up paint. The parts department 
can look up the paint code and sell you the correct one. If you 
have the paint code, any autobody supply store can make you a 
larger amount.

For very small chips you can use medium weight porous paper and 
just dab a sharp corner of the paper with a small mound of paint 
on it in the chip. For very thin scratches, you can use a thin 
paper towel dabbed in paint and then just sort of drag it along 
the scratch. For larger scratches, matchsticks or paint brushes 
work well.  Make sure to have a towel and some paint thinner 
handy in case you make a mess.

It is best to apply touch-up paint in many thin layers to fill a 
chip, rather than fewer thick layers.  Fill the chip until it is 
slightly higher than the surrounding body, then use a polishing 
compound to equalize the height.  Finally, wax the chip and 
surrounding area to protect it.