How can i change the color of a graphics object?

Questions
,
1

I have a number of graphics objects, separately produced. I would like to combine them into one graphic, but color each one differently, so as to distinguish one from another. Something like

Show[
  Style[graph1,Red],
  Style[graph2,Green]
]

but this doesn’t work for me. Is there anyway to do this?

Thank you
Dave Golber

2

Graphics[{{Red, Disk[{0, 0}, 1]}, {Green, Disk[{1, 1}, 1]}}]

circles.png
circles.png360×359 3.17 KB

3

I should also mention that the grouping I used above is not necessary. I often produce that in building the graphic list, but it is only the order that matters.

Graphics[{Blue, Disk[{-1, -1}, 1], Disk[{0, 0}, .5], Yellow, 
  Disk[{1, 1}, 1]}]

circles2.png
circles2.png360×359 3.06 KB

4

Thanks for trying to help, but this isn’t my situation. Let me be more explicit:

gr1=ListPlot@elaborate calculation … which take several minutes and I don’t want to run it again

gr2=ListPlot@ another elaborate calculation … which take several minutes and I don’t want to run it again

When I made gr1 and gr2, I did’t plan on showing them together, so I didn’t do anything special about the colors. Now I want to put them together, and have gr1 in one color and gr2 in another color. Sop I want to do something like

5

Thanks for trying to help, but this isn’t my situation. Let me be more explicit:

gr1=ListPlot@elaborate calculation … which takes several minutes and I don’t want to run it again

gr2=ListPlot@ another elaborate calculation … which takes several minutes and I don’t want to run it again

When I made gr1 and gr2, I didn’t plan on showing them together, so I didn’t do anything special about the colors. Now I want to put them together, and have gr1 in one color and gr2 in another color. So I want to do something like

Show[
Style[gr1,Red],
Style[gr2,Green]
]

but this doesn’t work.

6

Documentation on Show says “Options explicitly specified in Show override those included in the graphics expression” so I hoped that something like

Show[{p1,p2}, PlotStyle->{Red,Green}]

would work. But it doesn’t. I think it would be very useful to be able to combine previously generated graphics in a single plot as you want. Particularly since we would be able to do the basic work without worrying about setting things up for later display. But I don’t know how to do this – maybe others will comment?

7

The PlotStyle option gets hard-wired into the main Graphics data, and Show has no power on it. You may try with a replacement rule like

gr = ListPlot[{1, 2, 3}]
gr[[1]] // InputForm
gr /. RGBColor[___] -> Red
8

Thank you very much. This works … basically.

Use // to see what the graphics object really is. In my case, it’s got Hue in it. So

Starting with graphics object gr, to set the color to Red, do

grRed = gr/.Hue[ _ , _ , _ ]->H[0,1,1]