Just like Luca said, color psychology can do wonders with your marketing campaigns. In some cases you can dramatically increase your conversions by just changing the color of a button or the headline.
The best colors for action taking buttons are as follows: Yellow, orange, gold, blue and green (people are naturally attracted to colors like gold or similar to). This may change depending on the niche and what you are advertising but, it usually is like that.
I recommend you run a quick google search for the best action taking colors in advertising and the importance of PICTURES (pictures are known to get awesome increases in conversions, run the search to know why, just don't over do it and place more than one image).
Hope this information helps you increase your conversions in your marketing campaigns.
To your success,
Jonathan N