Desert Style Tilemap

I know there is the forest, dungeon, miscellaneous, etc. But I’m trying to create a desert style game and there isn’t enough yellows, well really any color to use. Does anyone know how to create this style in Microsoft makecode arcade tilemaps?
Edit: Whoever created this Arcade thing is magnificent, but really could use some new colors, new tile maps, etc.

If you want, you can change any of the colors (besides 0 / clear); you can either do this with an extension I wrote a while back (see Change color palette dynamically) or by changing the palette in the settings file, which is a bit more annoying but will make the colors show up in the image editor (https://learn.adafruit.com/custom-color-palettes-for-makecode-arcade-games seems like a good guide at a glance)

Thank you.