Remember that the drawRGB() method appears only in MIDP2.0, not MIDP1.0.
The colour values are not numerically equivalent. The integer values for MIDP2.0 have 8 bits for each Alpha, Red, Green and Blue. The short values you have for the Nokia API are four bits for each channel (assuming they are formatted "4444").
For example, you have a colour for the Nokia with the value 0xF8A0 - these are Alpha (F), Red (8), Green (A) and Blue (0), so this is a fully opaque greenish-yellow. To show the same colour through the MIDP2.0 API, this needs to become 0xFF88AA00 (FF Alpha, 88 Red, AA Green, 00 Blue).