Recommend Chart will not highlight this category

[Look, More, What]

Hi, I'm the excel expert at my workplace, but I'm a complete moron because I'm stuck on this.

I'm using Excel 2013 and I don't see a way to go into customizing other than going with what Excel's little multiple choice area. But here's the situation.

I'm making a chart off three things: Date, Gas Station, and Amount Charged.

I only went to two gas stations this year and I want to show a good line graph showing this. Excel does this, because the dates and gas stations are at the bottom and the left side is all Amount Charged. However, I can't seem to highlight the gas stations. I'd basically like Gas Station #1 to be red and Gas Station #2 to be blue, and the markers to follow suit.