Visit art supply websites to view the available fluorescent acrylic paints. Paints come in jars, bottles and tubes and in varying viscosities (thickness and resistance to flow). You can purchase paint this way or mix your own.
Combine a clear acrylic medium (available at art and craft supply stores) with fluorescent pigment, sometimes called "glow powder" to make your own fluorescent acrylic paint. The mixing ratio is 10 parts medium to one part pigment.
Mix a small amount of fluorescent paint before making large quantities so that you can be sure you like the result. Modify the ratio as necessary per pigment instructions and your artistic needs.