I don’t know, but I suppose there is no harm in trying.

Am interested to know as well I have A few pants like this….

I am not sure it would be same colour it could be lighter black. If noticeable dye again might make it darker second time.

It can’t hurt and would probably look a bit better!

Yes – the patches might still be noticeable, but they’ll be much less obvious.

Sorry I’m no help, I normally just use clothes like that as around the house ones lol. But it’s interesting to find out what others have done

Perhaps you could try some black fabric paint instead of dye.

Nope! You’ll need to completely remove all colour in pants and then re dye. My daughter left a pink jumper on the clothesline for way too long and it faded in the sun. I went to Spotlight for some dye and advice, and this is what they told me. She now wears it faded and patchy as it’s a trend now lol

Not so long ago I attempted to dye some shirts with bleach stains and it didn’t work. If you are dyeing something with a print or logo or stain, the color chosen for overdyeing will mix with the existing color(s) in the fabric and create new colors. In other words, the rules of color mixing apply.
There are colour removers on the market which prepares the garment for a more equal dye effect. You can buy it at Lincraft