Della, regarding your camera I do understand your frustration. I think most cameras have a lot of trouble rendering colors correctly for macros. Unless your camera has some specific issues with one color (for instance red can be extra difficult for some cameras) this often has to do with how the white balance is set internally. It's very hard for a camera processor to know exactly what color a bright flower should have and it's much easier for it to adjust white balance for a scene with more neutral colors. Personally I often need to change the white balance manually in post processing, often using several tools. It can be very hard to remove these color casts!
I'm going to assume that you with 'similar effects' mean the out of focus background and foreground? This is easier to achieve on cameras with larger sensors, but this is also very much a function of using a very long focal length and a low shooting angle. In this case I was at 500mm, but that is rather extreme and often you can get away with a shorter focal length.
Buying second hand (from a reputable source) sounds like a great idea to me, if you decide that you need/want to upgrade your tools
.