I am not a fan of using white to highlight any color other than near-whites, because white comes out transparent with one pass, and you don't actually *get* white.
For SMALL models (infantry sized) Wazkada (or however you spell it) or Evil Sunz are nice shades to brighten red, and Fire Dragon Bright or Troll Slayer Orange are nice to give a crisp highlight.
For LARGE models (vehicle sized), the reds are not visible, and even the oranges can get lost -- it's a thin line on a very large surface. Because of this, I use a color like Fire Dragon bright first, and then highlight again over many of the areas that would catch more light with Ungor Flesh.
Here is an example of a model I just finished, though it's Mephiston rather than a Khorne red -- with the edges highlighted in
FD Bright + Ungor Flesh:
Cadian flesh is also not bad.