The default highlight pen has a COLORREF value of 0xFFFFFF (white). This color will not work well with images that have many mid-range gray colors. A better selection for such cases would be 0xC0C0C0 (silver).
When working with automated annotations, change or obtain the color of the pen that is used for highlighting and selecting by calling the LAnnAutomation::SetAutoHilightPen or LAnnAutomation::GetAutoHilightPen function.
Medical Web Viewer .NET