How can I change the color of the gridlines of a Grid in WPF?

Question

I have a Grid (not a DataGrid, but a real Grid), with GridLines set to True. How can I change the color of the gridlines? Hardcoded in XAML is ok, since it is just for development-reasons.

<Grid ShowGridLines="True" />

Answer 1

Sorry, can't be done with ShowGridLines - you need to style the elements contained.

Exhibit A:

MSDN docs say "Only dotted lines are available because this property is intended as a design tool to debug layout problems and is not intended for use in production quality code. If you want lines inside a Grid, style the elements within the Grid to have borders."

Exhibit B - The WPF Source Code:

Notice the Brushes.Blue and Brushes.Yellow hard-coded in this sealed internal class which System.Windows.Controls.Grid uses to draw the lines.

From Grid.cs

    /// <summary>
    /// Helper to render grid lines. 
    /// </summary>
    internal class GridLinesRenderer : DrawingVisual 
    { 
        /// <summary>
        /// Static initialization 
        /// </summary>
        static GridLinesRenderer()
        {
            s_oddDashPen = new Pen(Brushes.Blue, c_penWidth); 
            DoubleCollection oddDashArray = new DoubleCollection();
            oddDashArray.Add(c_dashLength); 
            oddDashArray.Add(c_dashLength); 
            s_oddDashPen.DashStyle = new DashStyle(oddDashArray, 0);
            s_oddDashPen.DashCap = PenLineCap.Flat; 
            s_oddDashPen.Freeze();

            s_evenDashPen = new Pen(Brushes.Yellow, c_penWidth);
            DoubleCollection evenDashArray = new DoubleCollection(); 
            evenDashArray.Add(c_dashLength);
            evenDashArray.Add(c_dashLength); 
            s_evenDashPen.DashStyle = new DashStyle(evenDashArray, c_dashLength); 
            s_evenDashPen.DashCap = PenLineCap.Flat;
            s_evenDashPen.Freeze(); 
        }