I am just getting in to pure data but have used max/msp for 3 or 4 years. im pissed that i have to buy jitter just to display multiple graphs/composite them in max so im getting into pd.

is it possible when displaying an array to change the line thickness and color of each individual graph?

Not with arrays. You can use Pd's graphical data structures to make some crude custom guis, and they do plot arrays that allow you to change color and thickness. But it's not the most intuitive thing in the world. Another option would be to use the GEM or Gridflow libraries to make your own display.

The gui is really NOT the reason to be switch from Max to Pd.

I know what you mean about having to buy Jitter, though. I have Max and Ableton Live, and I simply can't justify dropping another $100 just to make them talk to each other.

i thought max integrates into ableton automaticly. I cant remember having to pay extra for that...

I just realised the lcd in max allows you to do it.