If you’ve ever had to generate a color scheme (say for a website) but didn’t go it professionally, the availability of color wheel resources on the web is pretty depressing. Lots of people want to teach you about color, which isn’t bad, but few enable you to do real color design, such as generating a tetrad color scheme. You can buy an app for it, but I don’t want to spend $40 for something I do once a year.
But, this morning as I fuddle with this site, I finally found the motherlode; [ws] Color Scheme Generator. This is an awesome tool: triads, tetrads, color blindness simulator. A very robust tool, online. Check it out.