Rosco has come out with a sophisticated tool for selecting gels and lighting colors with the new LED Mixbook.
As we continue into a new, LED-driven future, where you can create nearly whatever color light you want with the press of a button, Rosco has come out with a new device that aims to help filmmakers identify what color light they precisely might want to use. The new unit is called a Mixbook; a hand held (or tripod mountable) LED unit that can create any color of light you might want to help you make decisions about what lighting units to rent or gels to buy for a particular job.
This device seems like it will be most useful in pre-production, when there is still time to make decisions based on the information, it gives you. Say you are working on a heavily tungsten job (which still happens, for budget reasons as much as anything else), and you need to put together your gel order. Filmmakers could use this little box to test various light colors on key wardrobe or set pieces to see how the light will interact before placing a large gel order, which would be a nice way to cut down on wasted ordering.
Source: No Film School