ssd1331 using RGB instead of hex with the adafruit library?

I am working on a project where it is possible to change the color on a oled screen using 3 values (R, G,B) however the adafruit library for the ssd1331 uses hex for this. I've looked up some converters but all of them have had errors with setting the color to pure blue (resulting in a yellowish green)
does anyone know how to convert a rgb value to a hex value?

0 , 0 , 255 = 0x07E0

0 , 0 , 255 = 0x07E0 is in hex 0x00, 0x00, 0xFF. You can use an on line hex calculator. The 3 colors are 3 different numbers or 3 bytes of data coma separated.

my bad was just going based off the example given in their library. its fine that i can use colors like but I want to be able to use dials and all that to just make the colors on the spot. which doesn’t seem possible to do with hex. just like you would do when you have a rgb led and you have 3 potentiometers connected to make colors with it.