Select Color and Linetype independently? - Graphics

Hello,

I apologize if this question has been asked frequently before but I
could not find postings to this question.

Is there a human-achievable possibility to choose the line shape (i.e.
solid, dotted, dashed etc.) independently from color? For example, to
plot a solid red curve and two blue curves, one solid, one dotted? In
the Gnuplot Manual I can only find linetypes consisting of shape AND
color. I know about the possibility to plot all lines solid but that is
not what I want to do.

Thanks for any help!

Ingo