the ToneMap shader in SweetFX takes inputs between 0 to 2.55 on all three values for FogColor, while the ReShade version takes inputs between 0 and 1.0.

~~so to convert the two, divide the SweetFX FogColor values by 2.55.~~

in this case, the values are 0.078, 0.882, and 0.941.

EDIT: actually, the shader itself is already converting the values for you, so you just input them in the reshade UI, ignoring the decimal point. in this case, it's 20, 225, 240.