It's a little more complicated than that. For starters, you'll need to use the number sign before any of the pipes you use. The pipe takes a color just like all the other letters. But, since it's invisible, it appears that a color has been skipped. So, if you use 7 pipes between two letters, it makes those two letters the same color. The problem is that 7 pipes leave a big space between letters, but it has an easy solution. All you have to do is adjust the spacing with §1 placed at the beginning of the string. You can use other numbers (or characters) after § to adjust the spacing, but §1 is the closest match to text without any pipes in between. Also, you don't need to use any pipes for spaces. Here's a quick example:

§1#||G|||||||r|||||||e|||||||e|||||||n |||||||t|||||||e|||||||x|||||||t|||||||.

That text will appear green (with decent spacing) in JJ2. Based on that example, you can adjust the color of all the letters by changing how many pipes you use right after the number sign:

0 pipes - Grey
1 pipe - Teal
2 pipes - Green
3 pipes - Red
4 pipes - Blue
5 pipes - Gold
6 pipes - Orange

You'll have to do some testing of your own for more customizing. Unfortunately, this method limits how many words you can use in your text string, so you'll have to keep your message short.