In DOTT, they look more pale/yellowish as they do on the painting on the back of the box of the v2 release (painted by Steve Purcell, not Gary Winnick @milanfahrnholz ) probably from staying inside and not eating enough vegetables.
Anyway…
Exactly!
See-Sixty-Four 
On the other hand, even in DOTT, Maniac Mansion is only a game based on the characters with a certain degree of artistic license, which is apparent by the extensive differences of the mansion and the recurring characters. Thus their appearance in DOTT can not be considered canon in the Maniac Mansion universe or vice versa. Having v1 on Ed’s computer in the English version but v2 in other languages doesn’t help either.
Timbleweed Park on the other hand, obviously takes place in the Maniac Mansion universe and is not related to DOTT. Thus we can easily take their appearance as Maniac Mansion canon.