You can indeed buy iridescent or pearlescent paints containing flakes of mica - Golden sells them. You can also buy iridescent medium to mix your own - not too expensive from an art shop, Reeves do one IIRC. Vallejo also make a metallic medium - mixing colours with ordinary metallics doesn't work so well as they have pigments in them already.
Cherno's picture uses colour-changing paint or interference paint, which flips between two or more colours depending on how the surface is angled to the light. Golden makes interference paints, quite expensive. You can buy colour-changing sprays from Humbrol or you could try places that sell car paints. The effect is often quite subtle on minis - it might look better on big flat vehicle panels.