I did a presentation today on some stuff at work and one of the things I talked about was people have different ideals about how the world works and this affects the design of apps.

One of the things I mentioned as a trivial example of this was the colour of a play button in a transport control (the things with play, fast forward, rewind, etc) in an app targeted towards kids.
I said that on one side someone says it should be green and on the other side someone says it should match the design and colour of the rest of the user interface (so if all the other buttons are white then play should be white)

I then mentioned that you only want it to be green because we've been taught that green means go from the traffic lights, and that it's a grown up ideal, not a kiddy thing.
I then mentioned that colour doesn't carry any meaning. Green isn't always going to mean 'go' (in some cases it means eco friendly), red isn't always going to mean 'stop' (in some cases it means courage)

I also mentioned that play buttons aren't always white (google image 'play button' or look at your tv remote)

Because of this and because the meaning of colour depends on the context I am able to say it has no meaning. Meaning of colour is arbitrary. In my mind this makes colour meaningless and it only invokes emotion not meaning.

what do you guys think?