Change line color?

I'm having trouble with an expression. I'm trying to change the color of my lines in SSRS. I really just want to make the field RunningTotalThisYr orange, RunningTotalLastYr black, and Goal red. (As a side note, I'm just using "Goal" to put a threshold line to see how close we are to meeting our goal). Here's what I've tried:

=Switch(Fields!RunningTotalThisYr.Value > 0, "Orange", Fields!RunningTotalLastYr.Value > 0, "Black", Fields!Goal.Value > 0, "Red")

Here is the dataset:

Here is the result:

Any help is appreciated :-)