Advanced! focus / caret problem

i made a text editor. i have a problem when my text is on a black background and i want to select a word in this text to change its format, cause the selection box (from getBeginIndex() to getEndIndex()) is also black on default in flash. and i did not find any scripting way to change that. i hope you know what i mean.
if you place now your mouse on my text here and try to select the first 3 words “i made a”, you will have to drag your mouse pressed on these 3 words and you will see a blue rectangle behind my words which you selected here. in flash it’s gonna be a black rectangle and i would like to be able to control this colour. thanx for any ideas!!! i’m really stucked…