Yes I agree with grace the darker one is the better one to wear because it a contrast with the other colors and the lighter one looks too much like the skirt .

I wear a cardigan for my job every day. (that's how I get out of wearing a suit coat) I like the dark one but I personally think both would look great. I think the biggest thing is length. You want one that is going to be at least as long as the shirt. I think with that skirt and shirt if you have a cardigan with a shorter length then it is going to start looking busy and a little messy. Proportion is key.