Coppied from winamp/wa_dlg.h from the Winamp 2.9 ML SDK.

       1) gen.bmp has a generic window frame for plugins to use.
          its format is similar to the minibrowser's.
          In addition gen.bmp includes a font for the titlebar, in both
          highlight and no-highlight modes. The font is variable width,
          and it uses the first color before the letter A as the delimiter.
          The no-highlight form of letter must be the same width as the
          highlight form.
       2) genex.bmp has button and scrollbar images, as well as some individual
          pixels that describe the colors for the dialog. The button and
          scrollbar images should be self explanatory (note that the buttons
          have 4 pixel sized edges that are not stretched, and the center is
          stretched), and the scrollbars do something similar.
          The colors start at (48,0) and run every other pixel. The meaning
          of each pixel is:
            x=48: item background (background to edits, listviews etc)
            x=50: item foreground (text color of edit/listview, etc)
            x=52: window background (used to set the bg color for the dialog)
            x=54: button text color
            x=56: window text color
            x=58: color of dividers and sunken borders
            x=60: selection color for listviews/playlists/etc
            x=62: listview header background color
            x=64: listview header text color
            x=66: listview header frame top color
            x=68: listview header frame middle color
            x=70: listview header frame bottom color
            x=72: listview header empty color
            x=74: scrollbar foreground color
            x=76: scrollbar background color
            x=78: inverse scrollbar foreground color
            x=80: inverse scrollbar background color
            x=82: scrollbar dead area color