This may not work in every case because of the nature of materials and rendering but there is a way to make it work with the Principled BSDF shader at least.
After setting color of the object in principled shader…
Shader Tab > Settings Panel > Change blend mode to Alpha Blend instead of Opaque
Uncheck Show Backface (by default this gets checked (annoying) when you change to Alpha Blend
In principled shader change alpha to anything other than 1 (change to zero for complete transparency)
In Eevee, you will see the result on screen instantly.
If the object has multiple material colors, you will need to repeat those steps for all materials
If the fade in and out is part of the animation, you'll need to keyframe the alpha settings