I just bought an EagleTec mechanical keyboard with blue backlight, and like J. Chomel, found that I just needed to use a key combination to turn the backlight on or off, enable/disable "breathing" mode, or adjust the brightness.
In my case, I'm using it on LinuxMint 17, but it should work on other distributions also.
Here are the backlight functions that the keyboard supports:
"FN" + "SCRLK" = Backlight On/Off
"FN" + "HOME" = "Breathing" On/Off
"FN" + "-" = Lower Brightness
"FN" + "=" = Increase Brightness
The keyboard also supports other functions not related to the backlight, although I haven't tried most of them, as I have yet to determine what most of the functions are.
The ones that I do know to work are:
"FN" + "F2" = Lower Volume
"FN" + "F3" = Increase Volume
"FN" + "F9" = Open Email Application (Thunderbird, in my case)