When do toddlers know their colours?

[katepol]

Reason for asking is that we have colour blindness on both sides of the family (not sure how it is passed down though).

My DS sees to not have any conception of colour. He recognises lots of shapes, can name different kinds of tools, has a good vocab and speaks in sentences, so it seems odd he doesn't 'get' colours. He just says 'I don't know' when you ask (which as my MIL pointed out, is very odd - he usually has an answer for everything ). He does know names of colours btw.

I know my dds knew their colours by the age of two - DS is two and a half. Is it within the normal range to not know by now, or should we start to wonder about colour blindness. DP also knows someone who only sees in shades of grey, so is even more alert to the idea of colour blindness.
Ta for any help

My DCs were all about 2 and found pink, yellow and red the easiest to identify, perhaps because there is less variety of shades - green and blue were always the hardest and even at 3.5yrs they can get caught out on very dark greens and navy blue. Black & brown were tricky too.

I suppose opticians can only test for colour blindness when the child can explain what it is seeing??

It would be worth mentioning to GP/HV or better, an optician, to get their opinion.

I used to work in a preschool and I'd say 80 % of all the kids who started in my class knew most of their colours by age 3.

One lad in my class was diagnosed with CB at age 3.5 (roughly), he knew names for most colours but would always (as far as I remember) mix up reds and greens.

Have a chat with an optician, isn't there a simple test they can do?

It's well within normal range not to know by now. DS knew all his at around 21 months, but IIRC his nursery regarded that as quite early (and he got them all at once, like a switch being thrown -- one month we were at parents' evening discussing how he didn't know any of his colours, and a month later he had them all down pat).

There are colour blindness tests that can be done on fairly young children, I think, so may be worth talking to an optician in view of your family history.

My DD2 was well over 3 when she learned her colours, she didn't care what they were called, just knew which she liked best!!

For a long time with ds everything was blue! He clicked at 2.2, and started with Pink, yellow, green, orange, black... and if it's many colors, he says it's 'rainbow' color which I think is really sweet... How is his language generally?

Thanks everyone. Good to hear it is normal not to know colours, and that it can just click. I suppose my girls were better at sitting and doing so noticed things like colours more, whereas I suspect colours may all just be a blur to DS as he rampages through his frenetic life lol!
His speech isn't as good as his sisters at the same age, although better than average, but his physical skills are VERY well developed. He climbs, he does forward rolls, can pedal a bike (with stablisers) as he is too small to reach the pedals of a trike, and he can catch and kick a ball better than my 5 yr old - just don't ask him to kick the blue one, eh?

dd3 was about 3, I only realised she didn't before by reading mumsnet threads on the subject. then I did some quick hothousing so she could catch up with her mumsnet age group.

Don't think it's at all unusual to not know them at this age.
However given the other stuff he does know it seems a little surprising that he doesn't know colours. Too early to get worried though in my humble and completely amateur (!!) opinion.