Hello, I am trying to create a simple graph of three overlapping circles in a kind of Venn diagram. One circle is red, one is yellow, and one is blue. Where red and yellow overlap, I want the color to be orange. Where yellow and blue overlap, I want the color to be green. Where blue and red overlap, I want the color to be purple. Where they all overlap, I want the color to be black.

I have Googled various phrases that (to me, a muggle) describe what I want to do, but nothing comes up that tells me how to do it. I have also messed around in Inkscape quite a bit and have not found the answer. I did manage to have two of the circles show a merged color when they overlapped (they were on different layers) but the third circle stubbornly won't do the same thing!

Thanks for any assistance.

Create 3 Circles (ellipse tool, holding down ctrl). Set the Fill colours to Red, Yellow and Blue, No stroke colour. Position them so they overlap each other.

Drag-Select all three. Lower their opacity to 50% or so - use the box labelled O: near the bottom left of the screen.
That gets you colours from inkscape's colour-mixing algorithm, which probably isn't what you want, but might do.

To create shapes you can colour, set the opacity back to 100. Select a pair of circles (shift-click two), press ctrl-D, then Path->Intersectionsion (ctrl-*). Do this with each pair of circles, then with a pair of segments. Colour the created shapes as you wish.

Put each object onto a new layer (press ctrl+L to bring up the layers dialogue). Then, right-click on the layer and set the blending mode to multiply.