A very informal dinner - dressing up too much, or not enough?

[CMcG]

So, here's my questions: Should I swap the yellow shirt out for a white one, and switch to cream kilt hose? Or do you think I could make the yellow shirt work?
And will a waistcoat alone look out of place? I think I might be able to dig up the jacket that went with the waistcoat but: 1) it's most likely way to small by now. 2) it wasn't bought with a kilt in mind.

I would wear the yellow shirt because it seems more casual and fun than the starkness of a white one. Stick with black hose, unless your cream ones are the really thick, cable-knit ones, because otherwise they tend to look a) rented or b) like athletics socks. In the future you might want to invest in some coloured hose like lovat blue or lovat green.

A waistcoat with no jacket is OK, and please do not ever wear a regular jacket with the kilt because it will be too long and look sloppy. On second thought, check your waistcoat and make sure it isn't too long such that it would get in the way of your sporran... if you're worried about getting cold, a sweater is also a good option, as others have mentioned.

..
I'll try to get pictures up later, if I can and if you need them.

Pictures are always helpful with this sort of thing!