Thread by @BryanRenno

Diegetic storytelling can mean a lot of things but let's talk about how shapes, color and lines can be used to help the design. This is something both designers and environment artists should know

Its important to understand what the visuals are communicating to the players. It's something you can harness, or if you're not careful, message without meaning or intent. Depending on the intent, you can make it subtle (or not so subtle in this case)

For more subtle effects, the most effective way I've found is to focus lines & color in a way that leads the player's eyes, hopefully without them totally aware. This example (minus the giant box of text) is a wonderful example. The walls drive this but the floor tiles also helps

This goes back to the fundamental art concept of vanishing lines. This can be a much more subtle concept than just leading the player by putting a light somewhere. While it works in a lot of cases, sometimes you dont want to be so direct

The way you message to the player can be really direct and depending on the experience your game is working towards, may not be something you want to do. You might want the messaging to feel like it comes natural in the world. Hiding the intent is key here.

"Put a light in a space and players will need drawn to it like a moth to a flame" is one of the oldest tricks and can be useful. But, it all comes down to how it's used. Again, consider its motivation, context and intent in the actual world you're depicting. Does it fit?

This mindset can be applied to a lot of things in the world. Dont settle for "the player needs this" as your sole motivation for set dressing. It needs to feel logical and believable in that time and space. Its that attention to detail that elevates a space.

Color plays a huge part of this. This might be something artists carry the load on but dont discount your designers input on this too. The process is a collaborative one.

Also: when picking colors, consider what is believable AND thematically works with the space.

Color can affect a players mood and feelings about a space. Do not discount this either. Use it to your advantage to help guide the player towards certain feelings. If it's a narrative game, consider building out a macro for each space to help with the emotional throughline

But beyond narrative focused games you can apply this to any type of environment for any game. It's a subtle but effective way to help players feel a connection and empathy with the space. It takes work and vocal support but it's so worth it to see players react to it.

One last note:
A lot of examples here are 3D spaces, but you can also do this in 2D. Colors, values and shapes are essential to this. Think of how the stairs in this shot from Night in the Woods vary in hue and value.