What exactly is a "color"?
This coming week, we stay on the color theme and go monochromatic. Pick one hue (more on that below) and make your whole mosaic with it.
There are all sort of words to explain and describe color. It can get technical and confusing so for the sake of simplicity I'll give my quick 'n' dirty definitions of a few terms here to help you think about this challenge. You can also feel free to read about color and color theory online if you want more in-depth info (warning: you can lose days doing this!)
Hue: A hue is an element of the color wheel. In painting terms, the hue is the color of the pigment before any white or black has been added to it.
Shade: A hue + black (e.g. dark green)
Tone: A hue + grey
Tint: A hue + white (e.g. light green)
Monochromatic colors: All of the colors of a single hue (shades, tones and tints.)
Pick a hue, any hue and see where it leads you. If you don't think you have enough materials, make your substrate smaller and/or your tesserae bigger. Whether you think you have or not, you've been doing great so far so I know you can make it work!