This is a new composite image using data sets from two optical systems (system details under image):
M20 & M21 wide field (1.8deg X 1.2deg field)
Tighter Crop
Some different processing has been used, including LAB colour blending.
As far as colour goes, the Trifid itself is no just red and blue, rather it has areas of red/magenta, blue/white, turquoise/green and teal as well as dark dust in the nebulosity and I wanted to showcase all of these.
Mike