Here is a handy script that I have written to auto colors trendlines.
Simply place this in your "Scripts" directory and then draw trend lines. When done, go to your scripts and attach to the chart.
Bearish Color is applied to any trendlines drawn downwards.
Bullish Color is applied to any trendlines drawn upwards.
Bearish Color is applied to top horizontal line.
Bullish Color is applied to bottom horizontal line.
Horizontal Trendline color is applied to all other horizontal lines.
Download the Script here:
Auto Color Trendlines.ex4 Auto Color Trendlines.mq4
For the latest version check here:
http://www.forexfactory.com/showthread.php?t=536082