[e2] Color Gradient Function

20 step red/green gradient function

The color gradient function allow colorize any source in 5% steps.
Define the source, minimum and maximum value (constant or , for example, bb (or any other channel)).

Versionshinweise:

Added the bollinger bands on top of rsi to use the bands as the gradient's min and max values.

Added color themes: Red and Green, Red and Blue, Blue and White, Rainbow

Versionshinweise:

Color theme code hidden inside the function.
So now you can use the same function to colorize multiple plots and flip (or not) the gradient separately for every function call.
f_col_grad ( source, min_source, max_source, color_theme , color_flip ).

Versionshinweise:

- Code clean up

Versionshinweise:

Major update:
- Color gradient moved into array
- 3 additional gradients
- Indicator inputs hardcoded
- Code refactor

Versionshinweise:

.