Is there a way to change the color of Missing entries in GraphBuilder when using a gradient?
Most likely in similar manner as you can modify the gradient (creating custom color theme)
Graph Builder( Include Missing Categories(1), Variables(X(:sex), Y(:age), Color(:weight)), Elements(Points(X, Y, Legend(10))), SendToReport( Dispatch( {}, "400", ScaleBox, {Legend Model( 10, Properties( 0, {gradient( {Color Theme( {"Blue to Gray to Red Copy", 4099, {{42, 63, 255}, {192, 192, 192}, {252, 11, 11}, Missing({0, 0, 160})}, 65, 1} ), Width(12)} )}, Item ID("weight", 1) ) )} ) ) )