Prepare green purée by soaking spinach, cilantro, and roasted Serrano pepper in warm water to soften for blending, 15 minutes.
Prepare a few pieces of parchment paper for the tortilla press. Make sure the paper will cover the surface of the tortilla press to keep masa from sticking to it.
Pour ¼ masa harina into a mixing bowl. Add one of the liquids or purées into the bowl and knead to combine until dough turns into a solid color. Gradually add masa harina if the dough feels too wet or sticky. Gradually add liquid if the dough feels cracky or dry.
Make green purée. Blend spinach, cilantro, and roasted Serrano pepper with ¼ cup of warm water.
Once dough is ready, roll masa into a masa ball.
Repeat steps 1 and 2 with remaining masa and liquid.
Now that you have four different colored masa balls, create more golf sized balls using the masa from all four balls.
Center masa ball inside tortilla press inbetween two sheets of parchment paper. Close and press down until masa spreads out evenly.
Cook on a griddle in medium heat.
Raw tortillas can be refrigerated and stored in an air tight container for up to 3 days.