Googled the karaka tone - consider resene ash - closest to a creamy white when you see it on the exterior. Depending on your house style, (more cottage like) I'd contrast the karaka green with a near white tone rather than a khaki tone. More modern, more khaki.

Oops! Your trim looks grayish blue to me. Sorry, didn't see it is charcoal until afterwards...well in that case, I think I would still do gable and wrought iron as mentioned but then try a bright yellow, like SW's BEESWAX is paint color. Are you in the islands? Sorta has "that look". Envy : )

Sorry I am so late coming to your site - you are an inspiration to all, homeowners and advisers alike. For your planting advice, I suggest you call Merrifield Garden Center to see if they will come out your way. They currently have wonderful garden centers in Merrifield and Fairfax (both in Fairfax County) and a new one in Gainesville, but they may come further south to wherever you reside. (www.MerrifieldGardenCenter.com) Even if they don't send designers to your area, they are worth a trip to see their huge selection for a day of pleasure and inspiration, or to pick up some plants. Most of my clients are in the Fairfax and greater Washington area, but I am currently living out west below Front Royal, VA on the Shenandoah mountainside - wonderful views. cascio.offsite@gmail.com

This just popped up , but I see it is quite old . Did you decide on paint colours ? The roof looks almost a brown tone in the photos , but you say it is dark grey . I assume you don't want to paint that ? If you do , go more charcoal IMO . If you don't , I'm assumimg it will look several shades darker with your wall colour choices . There is a roller door on the garage that appears to be a nice shade of orangey yellow . Personally , I would go with your colour choices , but do all the doors ( roller doors , wooden doors ) and gutterings in that ochre shade . Your terrace I would do in a charcoal , but with the top rail either in the orangey yellow , or a really crisp white . I know that sounds a bit 70's ( although they would have added a lot of ranch brown back then haha ! ) but against the light grey I suspect it would work together well , and look the part .