I wear a kilt regularly (Church, fun, you name it), have worn one for 13 years now. I don't have a utilikilt but a standard 8 yards of wool pleated to set. No shots of me in mine, but here's my son in his.
As to colors, yes, most tartans are a Victorian invention, done after the suppression of the Scots after Proscription was passed. However, as tartans have meaning these days, there is no particular reason for a McDonald to wear Campbell colors merely because they like the color. It isn't wrong, per se, but odd all the same. I actually chose Black Watch because the Riddles have no official tartan being a small family and though I am McDonald, McDuffy, and others, I preferred Black Watch. That, you see, falls within the arguments against being picky of tartans, but also is a statement that I chose a tartan that belonged to no clan (or Clan Society in the US).
Ash