Repeat one color and vary another.
Repeat a neutral from the palette and let the pattern carry an accent. With a bold wall, a quiet rug can preserve that focal point. Retailer photos are not a reliable exact color match.
Check the actual footprint.
Mark the intended rug edges in the room. Account for the couch, table, doors and walking routes. A rug may extend beneath seating, while a coffee table needs clear floor space. Those are different placement rules.
Screen colors are a guide. Test physical samples in your home.
Keep exploring
What paint colors work with a gray couch?
What paint colors work with a beige couch?
Warm paint colors for your living room
Paint colors for a low-light living room
How to match curtains and wall colors