The Mini Grip has rather more brightly coloured handles than say the CASE work range(sort of mid yelow custard colour and very Trad!)But the Mini Grip is very easy to find in the workshop or garden because of the colour.I have one and think highly of it,but opt for thumb stud model not the hole.
Others to consider: The yello Jakets have been mentioned and I have a very pretty lockback in that, don't like blade etches usually but that wasp on the blade is wonderful.
GEC do range of Banana bone handled Traditionals
Bark River has a Rescue Yellow handle option.
Rough Rider has an EXCELLENT series called Old Yellow with a very nice union shield,I have a Gunstock, Sodbuster and Doctor in that series.There are others such as Toothpick,Sowbelly,Stockmans,Trappers etc All very nicely made and cheap to buy,they look and feel very decent.
German Eye and Moore Maker also offer some yellow handles.
Yellow is an excellent handle choice!