Which Color Tube for What Test? Your Everyday Tube Color Guide
If you’ve ever worked a busy morning draw, you know the moment: three patients waiting, two tubes in your hand, and your brain suddenly whispers, “Is glucose gray or gold?”
That pause is completely normal. Even seasoned phlebotomists sometimes double-check themselves. The truth is, those colored vacutainer color codes aren’t just decoration — each one is carefully designed to make a test run the way it’s supposed to.
At myOnsite Healthcare, our mobile team sees this every day. We draw for patients at home, in clinics, and for clinical trials. And since we aim for zero rejected samples, we thought we’d share a down-to-earth blood collection tube color guide that makes things simple to remember.
If you’re still learning or want to sharpen your technique, check out our guide on venipuncture techniques
First Things First: Order of Draw
Before we even touch the colors, let’s clear this up: the order matters. Additives from one tube can sneak into the next if you don’t follow the sequence. That tiny slip-up can ruin a test.
Here’s the usual order of draw for tubes:
- Blood cultures
- Light blue
- Red or Gold (serum tubes)
- Green
- Lavender / Pink
- Gray
- Royal blue (if ordered)
It’s not glamorous, but it saves headaches later.
Tube Colors Made Simple
Light Blue Top
- Additive: Sodium citrate
- What it’s for: Coagulation studies — PT/INR, aPTT, fibrinogen, D-dimer
- Tip from the field: It has to be filled right to the line. Anything less and the lab might toss it.
Red Top
- Additive: Nothing (glass) or clot activator (plastic)
- What it’s for: Drug levels, blood bank testing, plain serum work
- When to use: If the doctor wants “just serum, no gel.”
Gold / Tiger Top (SST)
- Additive: Clot activator + gel
- What it’s for: Most common chem panels, hormones, vitamin D
- Note: Needs a short clotting time before you spin it.
Green Top
- Additive: Heparin (sodium or lithium)
- What it’s for: Ammonia, stat chemistries, blood gases
- Why we like it: No need to wait for clotting — perfect for urgent samples.
Lavender Top
- Additive: EDTA
- What it’s for: CBC, A1c, ESR, hematology
- Heads-up: These fill fast — keep an eye on flow so you don’t overshoot.
Pink Top
- Additive: EDTA (blood bank grade)
- What it’s for: Crossmatching, antibody screens
- Easy mistake: Grabbing lavender instead — always check the label.
Gray Top
- Additive: Sodium fluoride + potassium oxalate
- What it’s for: Glucose, lactate, blood alcohol
- Neat trick: It stops glycolysis, so sugar levels don’t “drop” while the tube waits.
Royal Blue Top
- Additive: Depends — could be EDTA, could be none
- What it’s for: Heavy metals and trace elements (lead, zinc, copper)
- Important: These tubes are ultra-clean — only use them when the test calls for it.
Yellow Top
- Additive: ACD or SPS
- What it’s for: DNA testing, HLA typing, some blood cultures
- Reality check: You won’t pull these every day — they’re for special cases.
Quick Cheat Sheet: Tube Color Meanings & Additives
| Tube Color | Additive | Sample Type | Common Tests |
| Blood culture bottles | SPS or broth | Whole blood | Bacterial & fungal cultures |
| Light Blue | Sodium citrate | Plasma | PT/INR, aPTT, fibrinogen |
| Red | None or clot activator | Serum | Drug levels, serology, blood bank |
| Gold / Tiger | Clot activator + gel | Serum | CMP, Lipid panel, TSH, Vitamin D |
| Green | Heparin (lithium/sodium) | Plasma | Ammonia, ABG, stat chems |
| Lavender / Purple | EDTA | Whole blood | CBC, HbA1c, ESR |
| Pink | EDTA (blood bank grade) | Whole blood | Crossmatch, antibody screen |
| Gray | Sodium fluoride + oxalate | Plasma/serum | Glucose, lactate, alcohol |
| Royal Blue | EDTA / none / clot activator | Serum/plasma | Heavy metals, trace elements |
| Yellow | ACD or SPS | Whole blood | DNA, HLA typing, cultures |
Common Mix-Ups (and How to Dodge Them)
- Using lavender instead of pink for crossmatching → double-check labels
- Forgetting to fill the blue top completely → always prioritize it
- Dropping drug levels into gold instead of plain red → gel can mess with results
- Ignoring order of draw → contamination happens more than you’d think
LabCorp also emphasizes the importance of filling anticoagulant or preservative tubes completely to prevent hemolysis and inaccurate results
Why It Matters
At myOnsite Healthcare, these aren’t just classroom details. They affect real people — a patient waiting for a glucose result, a doctor adjusting a medication, or a trial that depends on flawless samples.
That’s why we:
- Keep a 0% sample rejection policy
- Hit a 95% on-time visit rate
- See 99% of patients say they’d do it again
Learn more about how we support patients with mobile phlebotomy services and home blood draws.