IF functions in excel - use multiple ones with the same outcome (explained)?

Here's my dilemma: I have columns of colours (red, blue, etc). For each there's either 0 or 1 (1 if the item has blue in it, 0 if not). BUT there can be 2 (or 10) colours in an item. Is there a way to formulate this in Excel?

I tried using IF, but this is limiting me to 2 conditions: if the red is false, then it'd go to blue, but I cannot seem to find a simultaneous way of showing both blue and red for an item.

For example: My skirt is both green and yellow. I have 0 for red, 0 for blue, 1 for green, 1 for yellow. I'd like this condensed in 1 column only, that would say: green, yellow (with a comma in between).

Help?