Very Simple EA based on one indicator

I need a very simple EA based only in one indicator. It should work on RENKO candles.

The indicator is the fast signal of the indicator THV 3 Trix v4.01 Div (attached)

OPEN order when: The indicator changes the colour from RED to GREEN and the candle is closed.

BUY order when: The indicator changes the colour from GREEN to RED and the candle is closed.

CLOSE: We close every order when the next candle opens. It doesn’t matter if it´s a winner or a loser, every order will be closed at the opening of the next candle. 

Please take into account:

     - We don’t care of the slope of the indicator, just the colour of it.

     -  Risk taken per trade: Set as input parameter to the expert advisor. (As default 1% of the total balance per order (e.g. When balance 1.000€ -> Order lots= 0.1 lot)). Important:  The lots per order increases at the same scale as the balance do (and the opposite if the balance decreases).

     - Maximum spread allowed: Set as input parameter to the expert advisor. (as default 2 pips)

Please see the picture for clarification. (I believe the EA should work either with regular candles or RENKO bars.)