I just looked in the Haynes manual wiring diagrams...
it shows in the instrument cluster attached to the ' charge indicator light' a diode and maybe a capacitor ... too small to see ....
And it shows 9 diodes at the alternator... I suspect 6 in the alternator and 3 in the regulator section...
So what I am saying the long way is that the soft glow /increasing in brightness is typical of an electrical switch operating it...as compared to ON/OFF.... and that they can degrade over time... your charging system may be off.... but it may just be that your indicator circuit is old and giving you bad indications... so don't spend too much money fixing one without checking out the other first...