Here's a picture with transparent background and drop shadow effect on the edges, which appear on transparency (32bit BMP with alpha channel):
Here's how it looks like when downconverted to 24-bit, and put on FBE200:
Here you find the original files attached: logo-transparent_32-24.zip (162.7 KB)
Here's another BMP test with white text on black background, background color set to black:
See the artifacts around the letters? These could be avoided by using proper transparancy handling (alpha channel in BMP or transparency in PNG)
Do you plan to rather support PNG? It takes less memory than BMP and has simpler transparency handling than BMP (and ffmpeg also handles it properly).