What you will need:
Fine brush (the best you can find, seriously, it will be worth it).
Acrylic paint of the colors you want to mix. (Buy mate, not bright).
Mix the acrylic paint to obtain the desired color. The mixture should be 4 parts acrylic paint and 1 part acrylic extender. Stir until you get a homogeneous and thick consistency.
My recommendation: leave the original lip so you can have a guide to paint them. First align them using a fine brush and fixing the shape to keep the sharp edges and corners. Then, take more color with the brush and slowly fill the lips of your Blythe doll.
If your mix is too light, you will see the original color of the lips. If that is the case, put a wet handkerchief over your lips and try to thicken the mixture by adding more paint. Let it dry when you’re satisfied with the color, thickness and consistency.
Beware of air bubbles. If this is the case, raise with the brush tip if there is any.
Let dry for approximately 12 hours.
Use the toothpick to further refine the corners and edges.
If you do not like the color or the final result, wash the paint with hot water and soap, being careful not to let the water ruin the rest of the makeup, in case of speaking, make another personalization to the face of your Blythe doll. If you have a hard time removing it, rub your lips with alcohol, that’s the trick.
If you like it, you can seal the color with the craft varnish. Again, let it sit overnight to ensure it dries completely.