ThinPrep (TP) Papanicolaou (Pap) samples containing excessive blood often result in unsatisfactory preparations, possibly leading to undetected gynecologic disease, and added inconvenience to patients and clinicians. Reprocessing of these samples with a glacial acetic acid wash is effective at eliminating blood, providing satisfactory preparation and detection of lesions. However, it increases laboratory costs and decreases work flow efficiency. We report the use of a color standard for gauging the necessity of performing a glacial acetic acid wash before TP processing. This "preprocessing" was found to reduce the costs associated with reprocessing by 48%, while maintaining high preparation quality by improved sample adequacy.