After creating the initial scatterplot from the table above (using Graph/Scatterplot Matrix), right-click on the graph and select "Row Legend". This dialog box appears:
![MathBasilisk1p6_0-1671707847936.png MathBasilisk1p6_0-1671707847936.png](https://community.jmp.com/t5/image/serverpage/image-id/48617iFD32893A2166F712/image-size/medium?v=v2&px=400)
Select "Color" and JMP automatically assigns colors to the categorical variable using "JMP Default" setting in the colors pull-down option. This can be changed but I left it as-is. Note that Markers is pre-selected as "None". I left this as is. Pressed ok.
On the resulting graph, I again right-clicked and selected "Row Legend". And I see this:
![MathBasilisk1p6_1-1671708164725.png MathBasilisk1p6_1-1671708164725.png](https://community.jmp.com/t5/image/serverpage/image-id/48618i79781323F751842A/image-size/medium?v=v2&px=400)
When I click on "Shape" under columns, note that JMP assumes that I want to use this column to again assign a color. I have to do two things. First, I have to select a marker scheme from the "Markers" pull-down menu. I chose "Solid" like this:
![MathBasilisk1p6_2-1671708372308.png MathBasilisk1p6_2-1671708372308.png](https://community.jmp.com/t5/image/serverpage/image-id/48619iDEAD99D7F6AF54E3/image-size/medium?v=v2&px=400)
Then, for the most important step, I have to click on the Colors menu and change the pre-selected JMP Default" option to the "None" option which is "hidden" all the way at the top of the pull-down menu. Here:
![MathBasilisk1p6_3-1671708660064.png MathBasilisk1p6_3-1671708660064.png](https://community.jmp.com/t5/image/serverpage/image-id/48620i59091C4AF2CD6447/image-size/medium?v=v2&px=400)
Then click on ok. To get the final graph with two legends.
![MathBasilisk1p6_4-1671708794622.png MathBasilisk1p6_4-1671708794622.png](https://community.jmp.com/t5/image/serverpage/image-id/48621iFC92A87F52E9846C/image-size/medium?v=v2&px=400)
This is what I want.
The combination of the pre-selected Color menu-item and the "None" hidden all the way at the top cost me hoursOfFun (mostly searching through documentation and posts). Maybe this dialog box needs a bit of tweaking. It's the same that is under "Rows/Color or mark by column . . . " so it's a fairly important bit of kit.
Hope this helps someone else save some time.