Change colour with age

[cagey5]

The attached image is from a tutorial I followed a while back. It shows a frame from an animation where a stream of stars and circles were generated and the colour changes over life. I know how to do that with voxels easily enough but can't for the life of me recall how I would do it with these shapes or for that matter how I would generate a mix of stars and circles.
Can anyone point me to the tutorial in question? Possibly one of Dans or shed any light on the colour change over life..

Thanks

[cagey5]

Yep. That seems to be the one. I thought it was HV sprites but couldn't get the colour change over life dialled in correctly. But by unchecking the 'use color' option and using the gradient, it all came back. Thanks for the pointer.