Here is something you can do that will achieve your goal:
Get one of those fat pale pink pencils, slightly shimmery.
Now draw a line around the outside of your lips. If your skin is very pale, you probably don't even need to blend it.
Apply the lip color of your choice, then -
Take a lip gloss or color that is several shades lighter than your lip color, and bop the very center of each lip lightly with it, blend the edges just a smoosh. What you are doing is making a highlight, be careful not to mess up your lip line, keep it right in the vertical and horizontal center of each lip.
Doing these things will catch the light, and make it look like there is more lip there than there really is.