As with the average person, most of the time that I contour I choose to use my bronzer. Not because I necessarily prefer to use my bronzer, it just always happens to be a bit more handy than other products at the time. However, most bronzers tend to have a golden, red, or orange undertone since, after all, bronze is typically a warm color. So when I use the usual bronzer, (say NYC Sunny for example that I find to lean a bit red on my skin), as a contour I find that it doesn't really accomplish the shadow look that I'm going for. Remember, contouring is pretty much enhancing the different features of your face by creating shadows on the parts that you want to recede. And if you look at your face, the natural shadows that form on you do not have a strong warm undertone to them: they're shadows, so they're pretty neutral. Therefore, if you're looking for a more accurate color to apply in the contour, try going for bronzers/contour products that have more neutral tones to them. This is no easy feat, as I find that even some products made specifically for contouring lean warm. But I do love E.L.F.'s Healthy Glow Bronzing Powder in Matte Bronze for contouring since it's a lot more neutral than the average bronzer. Benefit Hoola is also a bit more neutral than normal, although it's a bit light for me, but it is buildable so I can get a contour out of it if I work a little.
Do you know of any other neutral bronzers/contour products? They're kind of like needles in a haystack.