Making an owner-draw control aware of the VCL styles

Owner-draw controls are powerful. They allow you to completely adapt your GUI to the needs of your users and potentially enable your application to display data in a more familiar way. In the end, owner-draw controls improve the user's experience with the application. However, owner-draw controls do not always fit in well with the VCL custom styles. Why? Because if you try to draw something by yourself, you could be tempted to use a fixed color, such clRed or clYellow, or you could be tempted to use the operating system color, such as clBtnFace or clWindow. In doing so, your owner-draw controls will not be style aware and will be drawn in the same way regardless of the current VCL style. In this recipe, you'll learn how to make custom graphics that remain relevant to the selected VCL style.