Design a Logo For My Holistic Practice

I am an Holistic Practitioner and I need a logo for my practice. This logo has to have something to do with flowers, and done in green or purple, or both colors. I need this logo to be usable both in print mediums and the web, thus I need the original files to be able to adapt the logo to each publication I am going to make. On the suggestions you send, I want to see how it looks like on both clear and dark backgrounds, and I must be able to change the color if I need to. A vector file handout would be a plus.