0to255.com – find lighter/darker shades of colors
Color choosers are a dime a dozen online, but 0to255.com is a very nice one. Its stated purpose is to allow you to specify a color and then find shades that are darker and lighter than that color. It’s very well designed, aesthetically pleasing, and has the good sense to allow you to copy the hex value of the color with a single click.
I use it on a semi-regular basis to design Java Swing UIs; just a quick tip for the Java folks out there – when you have the hex code copied, you need to preface the hex string with 0x for the Color constructor to work correctly. In other words, if you are have the hex string #facade, you would create a Java color object with the command new Color(0xfacade). The 0x tells the Java compiler to treat the following text as hexadecimal.