A few things to take into consideration before chosing a solution, have a tan done yourself and look at the initial colour with the colour guide, what does it feel like, how long does it take to dry. Is there a smell to it? What does it look like the following day once the coolourguide has washed off. See how it wears off - it may take you a few more days before making your decision, but just remember your clients will be wanting a good result and your reputation sepends on it. DOn't always chose on price, the cheap route isn't always worth it, especially with solutions.
If you are looking for natural coloured solution, just remember to do the "tissue test" where you should drop a few droplets of tanning solution onto a tissue and watch what happens. If the colouring from the drops turn green, then this is an indicator to the artificial FD&C colourings within the solution, be careful with your storage as the solution will be more prone to turning green when the red colouring is exposed to air, light and heat. Make sure you order in small quantities and keep out of cars in this hot weather.
If the solution retains it's brown colouring, this will be a good sign that natural colourings have been used within the solution and shouldn't turn green.
Good luck with your choice.
Kind regards
Mandy