The Viaduct logging interface was improved a couple of weeks ago to make it even easier to see exactly what your processes are saying to you.
We're now show ANSI colours in the editor which makes things much more readable.
It's usually pretty simple to print these colours from your application. You can read more information about them on Wikipedia. I've included a few quick examples below in Ruby. You'll see I have extended the String class to provide an ansi method which accepts the escape codes.
class String
def ansi(*codes)
"\e[#{codes.join(';')}m#{self}\e[0m"
end
end
"This will be red".ansi(31)
"This will be yellow with a red background".ansi(33, 41)
"This will be green underlined".ansi(4, 32)
Viaduct currently supports 31-37 (foreground colours), 41-47 (background colours) as well as 1 (bold), 2 (faint), 3 (italic) & 4 (underline).