I have implemented in JLabeledCurrencyEdit (just for testing)
Property: NegativeDisplayFormat
Property: NegativeColor
You can get it in latest lazarus-ccr svn code (rev 5629) . Get, compile and install.
Example to use it:
New Application. Drop two JLabeledCurrencyEdit components in the form.
Set DisplayFormat to: #,0.00€
Set NegativeDisplayFormat to: (#,0.00)€
Set NegativeColor to: clRed
Set Alignment to: taRightJustify
Run the program. It will display 0.00€
type -5 after updated it will display in red: (5.00)€
You also can change default font color.
As you can see, there is no need for special StrToFloat.