I can confirm that for the Class 60, the panel2.cfg indicates (0,0,255) for the background while the color in the corresponding d3d\panelc.bmp is (0,0,254). And for the Class 73, the panel2.cfg indicates (0,0,255) while the color in the bv4\panel.bmp is (0,0,254), too. The fact that the corresponding parts in the bitmaps do no show up transparently is not a bug, but the intended way of processing the images. You can use Photoshop or
Paint.NET among many others to query color values, but for Photoshop, you should not enable Web Safe colors as Photoshop will round the actual color queried to the next matching web color, which then is (0,0,255), giving you a wrong impression of what the bitmap actually contains regarding color values