here's how the color chooser works:
goto edit studies by clicking on the beaker icon on the top bar of the chart and rightclick on the sdi_ivp study. this gives:
the labelColor plot only exists to pull in the color chooser widget that comes with plot objects, all visible manifestations of it are hidden.
click on the color box and you get the color chooser drop down:
click on one of the 9 standard colors then click ok/ok. when i click on dark blue the label color changes:
or click on the select button in the color chooser to choose a color from a broad palette of colors or input the explicit rgb values if you know them:
as always i maintain the revised source code in the original post for sdi_ivp