Livebearer fry are generally quite big, as far as Tropical fish fry go at any rate. Generally if the female is coloured, her fry, or majority of the fry will have similiar colouring, so if she is orange the fry should stand out easily. If you dont have another tank to remove her into for birthing, and your tank isnt heavily planted, i wouldnt worry too much anyway, the fry stand very little chance of surviving if the above is the case. If there are anymore questions, then you should post them in the Livebearer section of the site, and we would be more than happy to help.
Cheers Shae