Folder icons
https://files.facepunch.com/alexguthrie/1b0411b1/sbox-dev_ybsrWWIkvk.png
Asset types use game resource background color if available
Nav
Better lighting on material preview
Marginally better, just to differentiate from textures inside asset browser
https://files.facepunch.com/alexguthrie/1b0411b1/chrome_PKtw8FvsR0.png
Might revisit and make these animated or something later?
Test 'new entry' button, asset entries handle overlay & icon rendering themselves
New theming test for asset list
https://files.facepunch.com/alexguthrie/1b0411b1/NVIDIA_Overlay_BMbGEdG72f.png