Layout
Your main text color should be black on a white background. You can have other colors and background images on your website, but the background behind the black text should always be white. This is the easiest format to read. If you would study professionally written sales letters, you will learn that their layout is mostly white with mostly black text on them.
Color Scheme
Do not use too many colors for your sales letter. In other words, use not more than 4 to 5 colors in your sales letter. Furthermore, the color scheme must blend well with black text and white background.
Long Letter vs. Short Letter
Now, we have come to the age-old question in writing your sales letter: is writing long sales letter better than writing a short one – or vice-versa? You do not have to guess. The answer is: The long sales letter. Why? The more you write in your sales copy, the better. There is always a debate on whether a long sales letter works better than a short one. But the truth is that there is no debate whatsoever on this topic as long letter will, definitely, outsell the short one anytime. Yes, some people will say they do not like to read a long sales letter. When that happens, you know that they are NOT going to be your customer. Also, I should think that they would not have any patience with your product or service, either. Is this the type of customer you want? So, write a long and exciting sales letter. Produce an exciting sales letter that keeps your prospect to read from start to end. And if they like it, they will definitely look forward to another product from yours truly. This same secret will make back-selling easy. Make him see a good future he can get with the help of your product. Think in this logic and you will be on the right track. It did very well for successful movie directors and copywriters, so why should you be an exception? Besides, you are writing a sales letter, not a brochure. A brochure only informs your prospect about the features of your product. It does not sell. Your sales letter does.