The yellowish tint is intentional. I started by using a very light blue colour for the metal pieces, but already had a yellow one for the gold. I ended up using it on the gem and decided to mix both so I could use it on everything. I will probably end up playing with the red before this challenge is over.

As for the wood, I got 2 different palettes that I use all the time, but I was restricted on the amount of colours to use and ended up with that, because I could use it on some items.

Thanks for the help, very much appreciated!

You could make the medium red a bit lighter and the light red slightly darker maybe. Here's a quick edit I did, also I noticed your image has a yellowish tint to it so I had a go at correcting that too, what do you think.

 I tried using the red, but it had too much contrast to my eyes. Do you really recommend it?

Here's a test, would like to hear your thoughts before changing it :)

Nice and readable items apart from the book, I'd use the reds for the book cover which will make it stand out more.