DD is almost 2.5 yrs and doesn't know any of her colours. She knows all the colour names and will try and guess a colour if asked but never gets it right! She's got great speech, can say her alphabet and can recognise a few letters, can count items up to 20 etc so not really concerned but was just wondering if this was considered really behind for her age. My mum thinks she might be colour blind!! I'd never really thought about it and thought she'd learn them when ready (we talk about different colours regularly to expose her to them). Thoughts??