In my personal experience, making models stand out by painting differently doesn´t always turn out well, in fact, most of the times I did it I hated it. So what I recommend you do (if you are doubting) is to paint the basic structure of the standard red to fit your army and
then add more colors to it. For example you could paint the triangles in two different colors: one red and the next triangle some other color. To make that "other" color fit I see three options: paint it green, so there is contrast between the two colors (they are opposite in the color wheel), paint it orange or yellow, to add brightness to it, or to chose any other color but use some paint to make them match, like a wash, a highlight or a glaze.
But any ways it´s up to you how you do it