RGB Values not matching - weird conversion issues

Hello everyone,
I am trying to create “ball and stick” models of molecules in Blender 2.91.
Maybe some of you are familiar with the coloring convention. Carbon gets black, Hydrogen gets white, Nitrogen gets light blue, Oxygen gets red etc.
So far so good. But if I type in the RGB values/255, I get a color that is quite a bit off.

So for comparison, I used the corresponding HEX Value of the color. I get the correct color by looks, but if I multiply the “Blender RGB” values with 255, it is off again.

Any advise how to get the correct color using RGB values?

Here are some example values for Nitrogens “light blue”:
RGB: 143, 143, 255
RGB/255: 0.56, 0.56, 1
Blenders RGB Values when using HEX: 0.275, 0.275, 0.275, 1

Thank you,

Blender RGB values are linear, Value is non-linear.

0.275 ^ 0.45455 = 0.56 (sRGB)

Thanks so much for the quick answer!
I was trying to figure it out mathematically, but until trying exponential functions I would have lost a lot of time :smiley:

EDIT: for anyone else finding this in the future, here is a method to get correct values:

This is correct values for 3D workflow. sRGB is incorrect for 3D. If you want convert, you can easily create a node group. Or you can buy VSHADE System.