color coding values

[fishqqq]

I have a form which tracks budget numbers and i'd like to be able to
color code the current results.

[text52] = the total budget (text field)

[text54] = (=[Budget]-[Text48]) the current amount of budget used
(text field) - this field is set with a GREEN font

[red] = is a number field with the field size set to "double" and the
format set to percent. the user sets the value in this field, ie 25%,
and as soon as there is =<[red] left before going over budget than the
value in [text54] will be show in RED font.

[yellow] = is a number field with the field size set to "double" and
the format set to percent. the user sets the value in this field, ie
50%, and as soon as there is =<[yellow] left before going over budget
than the value in [text54] will be show in YELLOW font.

the formula to make this work would be something like: ([text52])-
([text52]*([red]) = the amt that [text54] has to be =< before the font
turns RED (otherwise it stays green)

[text52] = $100
[red] = 25%
so once [text54] = < $75 then the font in [text54] turns RED.

can anyone suggest how to set the control source in [text54] to change
colors like this?

thanks,
Steve