You could also pair the delica or endura with a dragonfly, if they wanted slightly smaller knives, or still the larger endura for him with the dfly for her. For her the Delica's come in purple (and its hard to find but there was a pink one made at one point), the dragonfly comes in pink or bright yellow (H1 "salt") and looks nearly the same.
The mini-grip is by far my favorite knive, I own multiple delica's and dfly's (my wife also has one of each) yet I carry the mini-grip every day. Its only a few bucks over your price, if I were you I would without a doubt get them the 550 & 555 combo in whatever colors you wanted. Not every color will be avaliable for the base (black) price but I know you can choose from yellow, blue, pink, red and i think dark/foliage green without it being an "upgrade" thus being reflected in the price, the only hard part will be finding a dealer that has both colors you want but you can find any of the basic colors readly.