protected virtual void DrawRibbonTabHighlightTop(Rectangle rect,
Color c4, Color c5,
MementoRibbonTabHighlight cache)
{
RectangleF hF = new RectangleF(rect.Left - 2, rect.Top - 1, rect.Width + 4, 6);
RectangleF vF = new RectangleF(rect.Left - 2, rect.Top + 1, rect.Width + 4, rect.Height - 1);
cache.topBorderBrush = new LinearGradientBrush(hF, Color.FromArgb(48, c5), Color.FromArgb(64, c5), 90f);
cache.borderVertBrush = new LinearGradientBrush(vF, c5, c4, 90f);
cache.outsideVertBrush = new LinearGradientBrush(vF, Color.FromArgb(48, c5), c5, 90f);
}