Black Lives Matter. Please consider donating to Black Girls Code today.
Dash HoloViews is now available! Check out the docs.

Change contours color

I am adding contour lines using this property:
contours: {
z: {
show: true,
usecolormap: true,
highlightcolor: “#000000”,
project: { z: true }
}
}
and it shows the vertical lines in white (like in this example).

How can I change the color of the vertical lines from white to black?