If I want to put these "yellow shirt", "red cap" and "holding a pen" altogether in one sentence, how should I do it?
"There is a group of people dressed in a yellow shirt, a red cap, and each holding a pen in their hand."
or
"There is a group of people dressed in yellow shirts, red caps, and holding a pen in their hands."
or
"There is a group of people dressed in yellow shirts, red caps, and holding pens in their hands."
or
"There is a group of people dressed in the same yellow shirt and red cap, and each holding a pen in their hand."
As you can see, I'm trying various combinations...

How would you tackle this?