Genetics
Short answer
Red-green color blindness usually follows X-linked recessive inheritance. Sons receive their X chromosome from their mother; daughters receive one from each parent.
The inheritance pattern differs for other forms.
In detail
Red-green color blindness is inherited in an X-linked recessive pattern. The red and green cone pigment genes sit on the X chromosome, so a son needs only the single altered copy he gets from his mother, while a daughter needs an altered copy from both parents.
That asymmetry produces the familiar numbers: about 1 in 12 men and about 1 in 200 women. A carrier mother gives each son a 50% chance of being affected; an affected father makes every daughter a carrier but cannot pass it to a son at all.
Pick each parent's color vision status to see the odds for each child. The complete answer table is printed below as well, so nothing here depends on the calculator loading.
Red-green color vision deficiency, X-linked recessive. Odds apply independently to each pregnancy.
The genes that build the red (L) and green (M) cone pigments sit next to each other on the X chromosome. Men have one X and one Y; women have two X chromosomes. That single fact drives the entire pattern. A man's only X came from his mother, so if it carries an altered pigment gene he is color blind — there is no second copy to fall back on. A woman with one altered copy still has a working copy on her other X, which is normally enough for typical color vision, so she is a carrier rather than affected.
The consequence is that color blindness travels through women and shows up in men. A carrier mother has an even chance of passing her altered X to each child. If that child is a son, he is affected; if a daughter, she becomes a carrier in turn. Nothing about a previous child changes the odds for the next one — each pregnancy is an independent coin flip.
An affected father contributes the mirror image. He passes his X to every daughter and his Y to every son, so he cannot pass red-green color blindness to a son at all, and every daughter he has becomes at least a carrier. That is the mechanism behind the classic pedigree where a trait appears in a grandfather, vanishes in his daughters, and returns in his grandsons.
Red-green color blindness is recessive, and X-linked. Recessive means one working copy masks one altered copy — which is why carrier women usually have normal color vision. X-linked means the gene sits on the X chromosome, which is why the recessive pattern produces such a lopsided result between the sexes rather than the even split an autosomal recessive trait would give.
The other forms follow different rules, and conflating them is the most common mistake in this topic. Blue-yellow (tritan) deficiency involves the S-cone gene on chromosome 7 — an autosome, not a sex chromosome — and is inherited in an autosomal dominant pattern, so one altered copy is enough and men and women are affected about equally. Complete achromatopsia is autosomal recessive and requires an altered copy from both parents.
So the answer to "is color blindness dominant or recessive" depends entirely on which color blindness. For the common red-green kind that nearly everyone means: recessive, X-linked.
A Punnett square for an X-linked trait uses the parents' sex chromosomes rather than a single gene pair. Write the mother's two X chromosomes along the top — one normal, one altered, if she is a carrier — and the father's X and Y down the side. Each of the four cells is an equally likely combination of one chromosome from each parent.
For a carrier mother and a father with normal color vision, the four cells come out as: an unaffected daughter, a carrier daughter, an unaffected son, and an affected son. That is where the two familiar 50% figures come from — half of daughters are carriers, half of sons are affected — and it is the single most commonly assigned version of this exercise.
The calculator above runs the same square for every combination of parents, including the cases that are easy to get wrong, such as an affected father with a non-carrier mother, where no son is affected but every daughter is a carrier.
These are probabilities for each pregnancy, calculated from the standard X-linked recessive model. They describe the odds before a child is born, not a measurement of any actual person, and they assume the family history you enter is accurate — which matters, because carrier status is invisible without testing and is frequently unknown.
The model also assumes the common red-green forms. It does not apply to blue-yellow deficiency, to achromatopsia, or to color vision changes acquired later in life from eye disease or medication, none of which are inherited in this pattern.
If the question is a real family-planning one rather than a curiosity, a genetic counsellor can work from actual family history and, where appropriate, genetic testing. Color vision testing of the people involved is a cheap and useful first step: knowing a father's type and degree, or confirming that a mother's own color vision is typical, sharpens the picture considerably.
The calculator is only as good as what you put in, and carrier status is invisible without testing. Confirming each parent's own color vision is the cheap first step — the free color blind test takes about two minutes, and there is a symbol-based version for children.
Probabilities from the standard X-linked recessive model. For real family-planning decisions, speak to a genetic counsellor.
Can women be color blind?
What carrier status means, and the 1-in-200 figure explained.
What causes color blindness
The cone biology behind the genetics, plus the acquired causes.
Color blindness statistics
Prevalence by sex, ancestry and type — the numbers this pattern produces.
Types of color blindness
Which forms are X-linked and which follow a different pattern entirely.
Last reviewed July 26, 2026. Educational information based on the standard X-linked recessive model, not genetic counselling. Real family history is often more complicated than any calculator.