I figured out a way to simulate the marbled metallic effect found in LEGO's pearlescent pieces.

Here's how to set it up in Scrubs' Blender template - (Here's a link to his template with it added)

It is adjustable - the scale of the Voronoi Texture controls the size of the metallic flakes - and the attributes of the Magic Texture control the marble effect. You can also tweak the roughness of the Glossy node to change how shiny the metallic is.

To speed it up you could try removing the Voronoi Texture. It's probably only noticeable in close ups.

The sample render shown here doesn't really do it justice - check out some of my recent renders (like this one) to see how it looks in action.

The metallic also reacts to changing light angles accurately, so it'll be great for animations too.

Enjoy!