During another discussion where LED colors came up, my curiousity about color mixing was piqued, so I did a little research and found this handy tool.
The OSRAM LED Color Calculator allows you to select various LED diodes, enter the dominant wavelength and intensity for each diode, and calculate the result.
https://www.osram.us/cb/tools-and-resources/applications/led-colorcalculator/index.jsp
The interface can be a little confusing at first, but hopefully some electronics DIY folks will find this useful for creating their own custom blade colors.