Huely is a tool I developed to help generate and export color pallets in a format that I can quickly drop into an SCSS, LESS or CSS file.
Typically I use a set of color variables - a primary color, secondary color and neutral color; each with two lighter shades and two darker shades; I find this generally covers the colors required by most designs.
With this system in mind, Huely allows you to set up a color pallet and automatically generates the lighter and darker shades based of each color, these shades can then be overridden if needed. The sidebar has tabs to change the format of the generated code.
One of the designers I work with found the tool useful even without needing the generated code so I fingured I'd make it public.