Making hot pink from coloured acrylics is not an easy task. The easiest way to get hot pink is to go buy the colour hot pink from a craft or art supplies store. But say you are in the middle of a project and you want to try to figure out how to make hot pink with what you have on hand without having to go to the store.
Mix a small amount of red and white paint together with a paint brush on a palette.
Add a touch of yellow paint and blue paint.
Adjust the shade by adding more of each colour until you get the desired colour.
Layer the paints as an alternative. Paint a layer with a very bright shade such as yellow or orange. Let it dry a little then add a layer of pink.
Experiment with a very small amount of paint so as not to be wasteful. It may take a lot of trial and error to get the right combination.
Making hot pink can be done, but it may not look as iridescent as the hot pink made by a paint manufacturer.