Use the HSL and RGB bars to find the desired colour, alternatively click the icon to select a colour from the standard Windows colour dialog.

Copies the current colour to the clipboard and adds the colour to the History list
Use this to pick a colour from the screen
Display the About dialog containing important program & contact information

Right clicking the History list on the right will display a popup menu

Delete - this deletes the currently selected colour
Clear - deletes all colours from the list
Export - saves the list as a HTML file

Right click the tray icon to quickly grab a colour from the screen!