Light colors. Like greens, baby blues, light purples, etc. When you think of weight loss, you aren't going to think of heavy colors like dark reds, blues, and especially black. Keep the colors very light. Good luck. Should of posted this in the graphics section.
Just like GhostRider103 said. Light Colours. I personally immediately see a light blue colour. Maybe just because most of the weighloss products I've promoted in the past, have a light blue colour. Furthermore, here is a lil secret: Light Blue has been proven over and over to be the colour that "triggers" Trust in people. If you make it your BG or some big part of your template, you will notice increased conversions. Any shades of light blue will do.
Thanks for your input. I think I'll go for light green, see what conversions are like and then switch to light blue and see if that makes a difference!
Greens, blues. Look what colours other people/companies are using, there is a reason they are all using similar colours.
Only light colors appear in my mind when I hear this phrase. Loosing weight is associated with lightweightness and nature. So, the best color combination is light green and white.