hi there,

maybe a solution

i'm a newbe so lets hope this works for you

on the particleShape tab

make the particles clouds
add the colour per particle atribute
create a ramp for this atribute

select the particles

goto hypershade

press the button with a square and arrow to the right
this will bring your particleconnection into your hypershade

add an
particlesampler (particle utilities)

add an

particleCloud (volumetric)

now connect the particle cloud to your particles
connect them with default you have to do this twice to get the atribute panel which you can close

then connect the particle sampler to your particle cloud
connect it to the colour

now you will see your particles in your software renderer or in mental ray

hope this will do for you

ieoie out........