The reason why I would take this more seriously is that you had a lot of trials here. You did this 10,000 times. If the true probability was 1 half, it's very low likelihood that you would have gotten this many magenta. So when you think about it, you're like, what's going on here? What are possible explanations for this? This I wouldn't have fretted about. After 10 experiments, not a big deal, but after 10,000, this would have caused me pause.