Select a color from the current palette to be used for drawing isolines. The default color is blue. A new window appears showing an array of all available colors. Click on a color field to select it. The last field shows the complete palette once more. If this is selected, the isoline color will be different corresponding to the value the isoline represents. Note: The selected color also affects the appearance of [Net-2D], if the mesh has 6-point triangles or 8- or 9-point quadrilaterals, i.e. midpoints of edges. Then the (inner) lines connecting such midpoints are drawn in the same color that is selected for isolines. If the multi-color field was selected, the inner lines of the grid elements are not drawn.