Some users of handhelds still own older Palm devices that are capable of displaying 4 or 16 levels of gray only. Meanwhile, increasing numbers of users are adopting newer, full-color devices. Generally, very good results can be obtained on Palm devices by designing banners optimized for a full color device, but which still look good on grey-scale devices. (This is not an issue on Pocket PC devices as virtually all of them have full color screens.) Since Palm banners will be viewed on both color and grayscale devices, we recommend you take care to ensure there is good contrast between elements (for instance, red on green or black might show up as the same shade of gray on a grayscale device and thus be indiscernible). You can test this out on an emulator, by creating a custom channel or by using the view grayscale features of your desktop graphics software.