Hi everyone, I've never posted here before, but was just wondering if anyone can offer some advice.
My 6yo is in Primary 2 at school (equivalent of Year 1 in England) and the school use a colour system to assess behaviour. Each child starts each day on green, and they get moved through yellow, orange and then red for behaviour which is deemed inappropriate. The children have a chance to earn their colour back to green, but if they are not on green by the end of the day they miss out on "choosing time", and instead spend they time reflecting on what they have done wrong.
I agree that this is a good system which teaches children to understand the consequences of their actions, but recently I've had a bit of an issue.
My son has been repeatedly put onto yellow the last few weeks, and when I ask him why I always get the same response, "I just couldn't think of the right answer". 
He has a great teacher, and until today I wasn't convinced she'd punish a child for this. Today my son came out of school and told me he'd been on red but had earned it back up to orange. I asked him why and was met with the same answer, so I spoke to his teacher, who said that he had spent an hour daydreaming instead of doing his work; but when she went and sat with him he had answered all of the questions within ten minutes.
I confirmed that my son had not been disruptive during this hour, and his teacher said that he had not, he had just been daydreaming.
We have had a similar conversation with this teacher before, my son seems to need constant approval of everything. He's like this at home too. It's almost like he has a fear of failure, despite our reassurance that it doesn't matter if things aren't right the first time. Also the fear seems a bit irrational as he has never failed at anything, so certainly doesn't have a negative experience of failing.
What I'm a bit angry about is that my child is being punished in the same way as, for example, a bully, and is now firmly under the impression that this behaviour is bad. I disagree. I feel like my son is being punished for not having confidence in his ability to complete the work.
I have tried and tried to look at all sides of this. I have tried to put myself in the position of his teacher, who has a class of twenty-five six year olds, all of whom have different needs, some of whom who will be in genuine need of extra help with the work, I realise that these children will take priority; however his teacher seems to be dismissing that there is a problem here, and marking it down as my son CAN do the work, so he must just not want to.
I really don't feel this is true, as I said he's the same at home.
I think the teacher is really good at her job, but I also feel that if this is a confidence issue for my son, punishing his personality, will only make the problem worse.
Another issue I have is that we have a reward system at home which my son cannot reach the top of unless he has achieved green at school. I feel like I can't dismiss his teacher's decision to change his colour, because that will teach my son that rules only apply when we agree with them, but at the same time, I don't feel like I can prevent my child achieving his rewards at home, when I don't agree with the reason he's been punished at school.
It's all really upsetting me, and giving me a headache to think about.
I have a few questions:
Am I overreacting?
If you were a teacher, would you punish for this? Why?
Should I take this further up the school, or just accept that while my son is at school he's not in my care and the teacher makes the final decision?
I really feel like I need to defend my son with this one.