A lot of high quality gaming mice and keyboards now give the ability to choose what color back lighting or led lighting you want.
Steel series, Logitech, Roccat, Corsair and Ducky all make good keyboards.. from what i've read avoid all RAZER products. Will depend on how much your willing to spend on one
Mice, So many mice to choose from Again, Corsair, steel series, Roccat and Saitek all make great mice, personally I have a Roccat mouse from 2011, it has switchable profiles, macros, choose from about 8 different colors cost me $40 and the quality is excellent.
As for a monitor I assumed that is where your budget of $400 came in
It depends on what size your after if "27 is sufficient by all means get a monitor. The refresh rates on the monitor will be faster then most TV's at that price point which overall is better for gaming.
For monitors I would suggest
http://www.newegg.com/Product/Product.aspx?Item=N82E16824014344 this monitor is used by most pro gamers due to it's high refresh rate and being aimed specifically at Gaming. I is $50 above your price point but atm it's 10% off
otherwise this is a 1080p IPS panel
http://www.newegg.com/Product/Product.aspx?Item=N82E16824236309 and aesthetically very nice a good friend of mine has this monitor and say's the picture and colour was as good as his Imac screen
But if over 27" is what your after go for a t.v will be far better bang for buck