Yeah you did a great job on the colors.
I really enjoy the pallet you used here, it has a nice smattering of evening sunset purples, and blues and I am a fan of the simple straight lines of the background details, as the world well in a public transit setting.
It is a little hard to tell if the character are sitting or standing, and I have seen a few standing only cars, but I figured out they are sitting from some of the slight cues.
The characters are fun, and I like how you caught there expression, as it makes it clear they are relaxed and engaged with each other, and I like your use of non verbal expression like the pictorial speech bubble and reaction lines.
The lighting is a little "mood lighting" but hitting the club on the train is a funny thought.
Thank you for making this.