Question: How to determin the color of "HIGHT LIGHT" in rich text editor control?

Hi,
 I would like to be able to select multiple line in richtext editor control
(Delphi 4) and each selecttion have differrent color (background & text
color), how can I do that ?   And if I cannot do that with multiple
selection, how can I set background color of a line in richtext  editor
control ?
Thank you,
Thit.