As described at ghostscript 5.50 (from RH6.2, /usr/doc/ghostscript-5.50/News.htm) this ghostscript version supports color mode with HP LJ 5.
But I can print only at b/w mode (as using previous versions). Section about HP LJ 4-5-6 printers at printerdb looks like at old versions (for
example from RH 6.0) that works only b/w ghostcript driver. May be it needs some additional parameters or something else?
looking at this.
We've got a new printing system, it is swuft.