I'm not really sure what your price range is, but if you're willing to hunt down some rarer models, I'm actually a fan of blue-handled knives.
First choice is hands-down the Spyderco Paramilitary 2 with blue G-10 and M390 steel. The blue is pretty bright - some people don't like it and it's often jokingly referred to as "smurf blue" - but I think it's a great color on a great EDC knife. Unfortunately, they were a limited run that's not currently available and you'll have to deal with secondary market pricing on them. Not a lot of fun.
Pics:
You'll notice there's also a dark forest green PM2 in those pics, another limited run, but maybe a bit easier to find at a somewhat reasonable price than the blue (CTS-204P steel in the green). And there was an orange version, as well (CTS-XHP steel) - I don't own one of them (though I would like to).
The PM2 is easily my top choice, but there's also a version of the Spyderco Domino out in CTS-204P steel with the same "smurf blue" G10 as the PM2. I just picked one of those up, and it seems quite nice - if you like flippers might be worth a look. Only a cruddy pic on this one, sorry:
If you like traditional folders, Great Eastern Cutlery has made some really nice patterns with blue camel bone, usually available through KnivesShipFree (in fact, I think I got an email from them today or yesterday about a new model in, and that's one of the options). The stain patterns on all of them are different and Derrick does a great job of taking individual shots of each one - you can pick how much white/blue color balance and what pattern you want yourself. I like a darker blue, and I like the #48 pattern - so I picked up one of these Hawthornes a while back:
Other blue/green/orange models worth noting:
Spyderco Delica and Endura come in blue, green, orange, and dark green - wonderful, lightweight modern lockbacks
Benchmade 940 comes in green - I don't like the blade shape myself but very lightweight for a 3.4" blade; a lot of people love it as an EDC
Benchmade 552 & 558 - Ritter Griptilians, available from knifeworks with M390 blades and orange scales
Benchmade 710-1401 and 810-1401 - also KW, also M390, layered blue/black scales.
Benchmade 665 APB, new Benchmade model and lock for this year, layered blue/black scales
And then of course you could get a model you like in a different color and have one of the craftsmen on here make you come scales in the color and material you want.
Hope that's enough to at least give you a few options to start looking!