Darkest spray tan solution available

[Jojo80]

Hi, I am new to the spray tan industry and have recently set up my own home business, I have used many samples from various companies and decided to settle with LA Tan, as myself and clients find the no odour and fade away quite appealing. However I have one particular client that wants to acheive a "David Dickinson" style tan, apparently this look is what the majority of young people want in my area. I have been using LA Tans darkest solution which is 18% called Disco Diva and when applied it does look very dark, however my client informed me that the morning after she showered it literally washed away and and the base colour left was nothing short of maybe a 6/8% look. Obviously I want to cater for all clients needs but I am having difficulty finding a tan that is so dark, that will stay. Can anybody recommend any products that will acheive a mahognany look but yet fade away as opposed to leaving patches. The clients skin tone is light Olive skin. Thankyou