Here is another accessibility tool presented as a Color Wheel where you can Hover over the wheel and the grey stripe to view colors. When you hover on an accessible color an "OK" message is displayed, otherwise change one color or both selecting foreground and background by left buttons. There is an explanation about different algorithms used in this tool for Deuteranopia, Protanopia and Tritanopia which are shown in the same time as you are changing colors exactly the way they should look for people having such color deficiency. The script is also available for download if you want to use it offline or try it on your own server, but anyway the script is written only in javascript.