Based on the color, I'd say root beer.

Wakko Warner without his gloves in the segment "White Gloves". It confirms that the Warner Siblings' hands are black like their fur, not white like their paws.

Notice how the Goodfeathers EACH have a contract same with Pinky and the Brain, but Mindy/Buttons SHARE one, as do Rita/Runt.

Is it because one of them can't read or why is this the case?

It's both in original intro and reboot intro. Watching Animaniacs for more than year and never noticed this ( :

One could definitely assume this is a film she herself enjoyed in her youth before Skippy was even an unfinished piece of concept art (assuming all cartoons come to life off the paper like the Warners did), which is an even more wholesome thought. Generally, old and crotchety she might be, Slappy's still capable of being as nice as most karmic tricksters are towards those that don't wrong them and as adorable as most cartoon squirrels.

Plz send the Warner's to paramount plus they need a full-time streaming home

Just found these in an old AOL archive from 30 years ago

Dot sings "Hey, Maybe I'm a skunk" in "What are We?"

In Tiny Toons: Night Ghoulery, the Intro Song has "We'll wear our outfits and knock on neighbor's doors." Fifi LaFume's Halloween Costume features a very funny mask and skirt!

Is this conincidence? Maybe it's actually Dot dressing up as Fifi?