[R] Color of points in a 3d plot of a PCA

[Alejandro González]

Dear all,
I'm trying to perform a principal components analysis of a sample of 
individuals, and to plot it in 3D, assigning different colors according 
to the population each individual belongs to. Given that the matrix I 
have to use for the PCA cannot contain cualitative variables (here, the 
population of origin), I have no idea how can I do this in R. ANy help?
Thanks in advance

Alejandro González
Departamento de Biodiversidad y Conservación
Real Jardín Botánico
Consejo Superior de Investigaciones Científicas

Claudio Moyano, 1
28014 Madrid, Spain

Tel +0034 914203017