What I would suggest here, to get the color specifics (RGB values, as well as Sat/Hue,etc)
Simply press the Print Screen Button, open your favorite Paint Program, and Eyedrop the color you want, use the same values in Construct 2 material editor to get the same color.
In case you didn't know, Print Screen works the exact same as "Copy" only it "Copies" your whole screen for pasting.