Giving feedback is difficult

Work placement went alright today, I gave feedback to 4 students, and 3 out of 4 went well. But the one that didn't go well is on my mind the most...

The class I was helping with was drawing masks based on African masks and patterns, and a girl asked me what colour she should paint the nose. Her mask had a lot of yellow, reds, and bits of green, blue, and purple. I completely blanked out and didn't know what to tell her. In the end, I told her to colour it in blue, but it seems it was the wrong choice. When I looked at her drawing some time later, she had added some red, obviously before the blue had dried, and the area was a bit messy. I guess she did not like the blue? And to be honest, it might have been better to have made it red, since the lips and the cheeks were red. I should have gone with the safest option.

But other than that, I hope I can be more useful to the older students. There is one that is interested in making a poster with a pop-art style, and hopefully I will be able to give him advice on techniques, and on how to use Photoshop.