you're on the right path-you need to introduce textures other than wood, say metal finishes, ceramics (like stools that can function as side table), stone etc. Basically everything that reflects light some more. Wood can be incorporated too, of course. Soft textures as well for a rug..yes to lighter rug, just pay close attention to function..I see you have small kids, so you want something easy to maintain, and not a tripping harazd. I'd vary colors too-don't make things too matched..I for example would switch pillows on your cranberry red sofa so it won't look like everything is supermatched to art above.
Bigger credenza would be indeed very useful..both for proportion (visually) and function(storage)
If you like patterns-introduce them. Some have very modern sensibility. Geometry, some large florals...
Depends how streamlined you want your furniture to be, also whether you're okay with sharp edges etc, so I hesitate to post exact suggestions.
But as an example..
light painted metal coffee table
https://shophorne.com/products/tier-coffee-table
interesting side table..used material(transparent plastic) makes it modern even though the lines mock traditional tablecloth
https://shophorne.com/products/grand-illusion-side-table-clear
you can find all sorts of ceramic stools on Anthropologie website ..not only there of course..but again, just to take a look. These are heavy enough not to break them, but if you're wary about it-check side tables with similar sensibility but made of different materials.
https://www.anthropologie.com/furniture-end-tables
check also their sister site. Urban Outfitters (and read reviews closely everywhere-can be a hit or a miss)
if you like funny..)
)https://www.urbanoutfitters.com/shop/birdy-side-table?category=tables&color=070&type=DEFAULT
(sorry for posting links instead of pics..not every site lets you to save)
there are so many cool rugs out there
this is probably too matchy..but I still like it. Modern, simple, interesting. 100% wool-wool is easier to tale care of
https://shophorne.com/collections/rugs/products/chandra-counterfeit-series-cou-18213
Add texture/light fabrics in your pillows..(you can find these anywhere), collect art that speaks to you, without worrying too much about colors..sure, take into account but don't let room dictate you too much, art is art..group small things together-say photo frames..add live plants-these immediately bring life, color, and texture to any room.
Knowing your budget will be helpful..since I love to spend other people's money as much as everybody..and been holding myself from some cool suggestions..))
Q
Everything
Q