RLE is Run Length Encoded, an "old" way to reduce the size of BMPs. These were often used in Win 3.x when disk space was much more exprensive and modems were a lot slower. (Note: Some RLE files don't work in VFP <s>.) Any graphics program will normally allow you to save BMP files in at least 4 different formats - OS/2 or Windows, RGB or RLE (not including the color depths or 1-bit, 4-bit, 8-bit and 24-bit).
Handling of colors is very much an individual thing. In general I tend to follow the Windows' standards, which basically say allow the user to change them through the color panel. I personally dislike when a programmer has decided that my taste in color schemes is "wrong" and his is "right". On the other hand I've had some customers that have well established corporate standards for all custom software, and you have to follow those.
The good news is that color and BMP handling is much easier and more flexible in VFP, assuming you go the whole OOP route.
While I've done conversions in a number of different levels, including running 2.x code under VFP, the best solution is to re-write. Maintenace on most converted stuff is at least frustratrating due to not having access to some of the new features, to plain impossible. (There are times when you have to do the changes in FP 2.x and then "reconvert" it - really not much fun after the 3-4th time.)
The most useful information I got on migrating, came from MicroEndeavours, Inc. They have a self study course VF610 "FoxPro 2.x to Visual FoxPro Migration Manual"
choose "Self-Study" at the left, then down near the bottom of the page.
This includes a number "why's" and "how to's", as well as some useful utilities to assist in the process. One of their techniques allows a gradual transition using a mixed model, but there are some downsides as you might expect. Also, one utility can create forms from the running code - you don't even have to have "screens" (.SCX files) to convert them. For the price - $249 that last time I checked - you can't get better advice. (I have no connection with them, other than being a satisfied customer.)
Rick