Oldest MacDonald sett?

[Damion]

The MacDonald Children. Note that there are four different tartans, three being worn by one person. The tartan on the jacket on the left is used for kilts nowadays.

Five different tartans if you count the sleeves of the older boy though the artist may have simply forgotten to add the horizontal stripes though the sett seems smaller too.
Might be coincidence, but maybe the older boy has two stripes either side of the wide band with his brother having one because he's the more senior.
The painting is from 1749 apparently.