My wife has a beautiful ankle-length skirt in my Sinclair Modern - but our tartans are from two different mills. As a result, her skirt emphasizes the blue; my kilt emphasizes the green.

The only caution we use is that when she wears a sash with her skirt, she wears one of the same bolt of material. When she wears a sash but other dress or skirt, she sometimes wears that sash or one from the same bolt as my kilt.