I’m not sure what brand you were looking at, but I know Redken has a Titanium line, which would impart a cool, slightly metallic finish to your dark brown hair, and minimize warm tones. You would want a Titanium color similar to your natural hair level (probably a level 5). It will also make your hair appear slightly darker. On pre-bleached pale yellow hair, a lighter shade of titanium helps to achieve a silvery finish. Redken’s Titanium colors can also be mixed with other colors from the same line, to help cool warm tones. However, don’t expect to put a level 8 titanium on your hair and have it lighten to that color. It is more used for toning bleached hair or adding a metallic sheen to natural or colored hair.