I Want to Modify my TDI indicator

I want to modify a few things on my TDI indicator

1. I want to change the Signal line to change color based on the slope of the signal line. So if the signal line is sloping down I want it to change color to Red, If it is sloping up I want it to change color to Green, If it is Flat I want it to change color to Black. 

signal line colors should be changeable.

2. I want to add a Standard deviation "midline". I want a midline that is half the distance from the Market Baseline line (yellow line) to the outer bands (blue lines). I want the line style and color to be changeable.

3. I want a "D" or a "C" to be displayed in the upper right corner of the TDI to tell me if the RSI is converging or diverging in relation to the signal line. (see screenshot for converging/diverging rules for this)

if RSI (Black line) is Below the Signal line (Red line) the "C" or "D" will be displayed RED, if RSI is Above the Signal line the "C" or D"D will be displayed GREEN (these colors and size should be changeable).

4. Add a 50 level line to the TDI

***SEE ATTACHED SCREENSHOTS***