Short answer: healthy semen is white, cream or light grey and slightly see-through. A yellow tint is usually normal, watery or clear usually means you've ejaculated recently, and red, pink or brown means blood, which the NHS says to get checked by a GP. Colour on its own can't tell you how fertile you are.
People in the UK search "yellow sperm" around 3,600 times a month, so you're far from alone in wondering.
Use the decoder, find your colour, and you'll have a sensible next step in under a minute.
Semen colour decoder
What is your colour telling you?
Match what you see, then add any signs.
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The decoder could not load. The colour chart below covers the same ground.
Colour chart as a table
| Colour | Usually means | What to do |
|---|---|---|
| White or grey | Normal semen. It starts as a gel and thins out within about 15 to 30 minutes | Nothing to do |
| Cream or slightly yellow | Normal, especially after a few days without ejaculating or as you get older | Nothing to do |
| Yellow | Time since you last ejaculated, age, or a little urine left in the tube. Less often, an infection | Check after your next couple of ejaculations. See your GP if it stays yellow or symptoms appear |
| Deep yellow or orange | Some medicines or vitamins, or infection | Book a routine GP appointment and take a list of your medicines and supplements |
| Green | Not explained by anything everyday, so worth a check | Book a routine GP appointment or visit a sexual health clinic |
| Pink or red | Blood in your semen. Most of the time no cause is found and it goes away within days or weeks | Book a routine GP appointment, as the NHS advises for any blood in semen. If you are 40 or over and it keeps happening, or you have pain, fever or burning: ask for an urgent GP appointment or contact NHS 111 |
| Brown, rust or dark | Older blood rather than fresh bleeding | Same as pink or red |
| Clear and colourless | Often follows ejaculating a lot. Looks alone cannot tell you whether sperm are present | Nothing to do. Trying for a year? Ask your GP about a semen analysis |
| Stays thick after an hour | Can happen with inflammation or gland problems | Check again over 2 weeks. If it persists and you are trying for a baby, ask your GP about a semen analysis |
| Very little or nothing | Can be retrograde ejaculation, where semen goes back into the bladder | Book a routine GP appointment |
Get help now: sudden, severe testicle pain means A&E or 999. Burning when peeing, fever, blood in your pee, or being unable to pee: ask for an urgent GP appointment or contact NHS 111.
Sources: NHS (blood in semen, prostatitis, UTIs, testicle pain), WHO laboratory manual 6th edition, NICE NG257, EAU 2026.
What Colour Should Sperm Be?
Normal semen is cream, white or light grey, and a little see-through. The World Health Organization's laboratory manual describes a normal sample as "cream/grey-opalescent".
The colour comes from the fluid made by your prostate and seminal vesicles, not from the sperm themselves, according to a 2023 review of semen appearance. That's why colour is a poor guide to sperm count.
If you'd rather watch than read, US urologist Dr Rena Malik runs through each colour from about 2:59. One difference: she says a single episode of blood usually settles by itself, while the NHS advice here is to see a GP anyway.
Why Is My Sperm Yellow?
A slight yellow tint is usually normal. The WHO manual says semen can look "slightly yellowish after longer abstinence times", so a few days without ejaculating is the most common reason. It also tends to yellow a little with age, and a trace of urine left in the tube can tint it.
I couldn't find a single human study showing that yellow semen affects fertility.
Yellow matters when it comes with something else:
- Pain, burning when you pee, or a fever: these can mean an infection such as prostatitis. Ask for an urgent GP appointment or contact NHS 111.
- Yellow skin or yellow whites of your eyes: that's jaundice, and it needs urgent help too.
- Deep yellow or orange that stays: book a routine GP appointment and take a list of your medicines and supplements.
Clear or Watery Sperm
Clear, thin semen usually just means you've ejaculated recently. In a 2024 analysis, a shorter gap between ejaculations meant about 1 ml less semen.
Can watery sperm get a woman pregnant? Yes. The WHO manual notes semen may look less cloudy if the sperm count is very low, but you can't judge the count by eye. Only a semen analysis can tell you that.
Red, Pink or Brown Sperm
Red or pink is fresh blood, and brown is older blood. The NHS says: "Most of the time it's not obvious what causes blood in semen and it goes away on its own."
In a 2021 review, 88.9% of cases with no cause found cleared up by themselves.
The NHS still says to see a GP for any blood in your semen, even once. Cancer is rare. It was found in about 3.5% of men seen for this in the research, nearly all of them over 40. So if you're 40 or over, or it keeps happening, book sooner rather than later. Ask for an urgent GP appointment or contact NHS 111 if:
- You're 40 or over and it keeps happening.
- You also have pain, a fever or burning when you pee.
- There's blood in your pee as well.
Some blood is common for a few weeks after a prostate biopsy, and for a short time after a vasectomy.
Green Sperm
Green isn't explained by anything everyday, so it's worth a check. Infection is the usual suspicion, though I couldn't find a study that proves it. Book a routine GP appointment, or go to a sexual health clinic.
Thick, Lumpy or Jelly-Like Sperm
Jelly lumps are normal at first. Semen comes out as a gel and turns runny, usually within 15 to 30 minutes, according to the WHO manual. A few small jelly bits that never dissolve don't seem to matter.
If it stays thick and stringy after an hour, every time, mention it to your GP, especially if you're trying for a baby.
What's Normal? The Quick Checklist
- Colour: white, cream or light grey. A slight yellow tint is fine.
- Texture: a gel that turns runny within about 15 to 30 minutes.
- Amount: 1.4 ml or more, just over a quarter of a teaspoon. A typical amount is around 3 ml.
- pH: 7.2 or more, which only a lab can measure.
- Smell: it varies. A strong smell of urine or rot is the one to get checked.
The amount and pH figures are the WHO reference values used in NICE guideline NG257. The WHO is clear that they are not a line between fertile and infertile.
Sperm Colour FAQ
Does yellow sperm mean I'm infertile?
No. A slight yellow tint is normal, and no human study links yellow semen to lower fertility. See your GP if it comes with pain, burning or a fever.
Is jelly-like sperm healthy?
Usually, yes. Semen starts as a gel and thins out within about 15 to 30 minutes.
Should I worry about blood in my sperm?
It often clears up by itself within days or weeks, but the NHS says to see a GP. Make it urgent if you have pain, a fever or blood in your pee, or you're 40 or over and it keeps happening.
Can you tell sperm count from the colour?
No. Colour and thickness are not reliable guides to sperm count. A semen analysis is the only way to know.
When should we see a GP about getting pregnant?
After a year of trying, or sooner if the woman is 36 or over, according to the NHS.
Keep Reading: Helpful TTC Guides
- Should you get a semen analysis?
- How to improve sperm quality naturally
- Boxers or briefs: does underwear really affect sperm?
This article gives general information, not a diagnosis. If you're worried, see your GP.
