[amibroker] Background Color

[K. Karunakaran]

I have tried the following to change the background color.  Black is the 
default background color.

TimeFrameSet(inDaily);
rsa=RSI(3);
TimeFrameRestore();
ra=TimeFrameExpand(rsa, inDaily);
Ca=IIf(ra>90, colorDarkGrey,colorBlack);
Plot( 1, "", Ca, styleArea | styleOwnScale | styleNoLabel, 0, 1 );

The color changes in the entire vertical area of the chart.  But,I would like 
to restrict the change in background color to the actual area of the candles.  
Someone, please help me with the codes.

My advance thanks

Warm Regards.

K Karunakaran