You don't adjust skin tone with translucency weight, especially lowering with large amount.
Translucency weight = Amount of light you allow to 'enter' the volume. It's a volumetric effect. De facto, it makes your volume no more a simple 'sandwich' of surface layers, but a 'sandwich' that is now pierce back and forth by light. That's also why it's instense effect to render.
The amount of light you allow to enter will be the pillar of your sub-scattering surface (SSS). To achieve credible and correct (by correct I mean working in any type of light intensity) skin SSS with Iray, you will need large amount a light to enter (something in the ~.75/~.90 range). Believe me or not, everything else is subpar.
Translucency color = This is the layer where skin tone change and adjustement can happen.
With large amount a light now entering your volume, the map you slot in translucency color (let's call it SSS_map) is now your "main" map for skin tone adjustement and calculated like this : SSS_Map*Translucency_color
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From there you got 2 roads :
Oudated one, you can see it while loading basic g8f model. SSS_map is a greyscale map with a plain red translucency_color. It's, yeah, no need to talk much about it.
More likely you want to slot as a SSS_map, either your diffuse map (the one you use in Base color), or a brighter version of it, with pure white as translucency_color (1,1,1).
Here a skin that use the diffuse map as a SSS_map :
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Let's say I want it more pale. Open your map in whatever your software of choice is, push for 33% more brigthness and save it as an exemple. [You can also remove the limit on Translucency color and push for (1.33/1.33/1.33), but it's not recommended]
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Now let's say I find the skin too red-ish in my taste. As translucency color act as a multiplayer, if I put (.90/1/1) in translucency color (those are RGB value) for exemple, I reduce red by 10%.
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Those are basics skin tone control.
Of course you can push a step further and edit hue/saturation/luminance or even sharpen thing a tad bit in your favorite software instead of just a simple brightness push.