Blood Collection Tube Cap Colors Explained (2026 Guide)

Blood collection tube colors help identify a product family, but color alone is insufficient to select a tube. Check the manufacturer, additive, draw volume and laboratory acceptance criteria. The examples below describe common BD Vacutainer conventions; they are not a universal chart for every brand.

Common cap colors and their additives

Cap example	Tube family	Check before ordering
Light blue	Citrate	Specified draw volume and fill indicator
Gold / SST	Serum separator	Gel specification and laboratory acceptance
Purple	EDTA	Required additive and volume
Green	Heparin	Heparin type and application
Grey	Fluoride/oxalate	Laboratory sample requirements

Order of draw

Use the current laboratory procedure for collection order and mixing. The linked BD chart is a dated, institution-specific example. CLSI PRE02 is the current document sold under the former GP41 code; a purchasing guide cannot replace a validated collection procedure.

PRP tubes

PRP/PRF tubes are a separate category selected by protocol, volume and cap/additive type rather than by the routine phlebotomy color scheme. Match the tube to your centrifuge and clinical protocol.

This article is a general reference and not a substitute for your laboratory's validated procedures.