The Moors in particular made wide use of plants and astronomical objects in huge wall coverings of tile. More subtle glaze colors occur in late northern European and English tile floor mosaics and pavements. Henry VII and Elizabeth I both had elaborate floor decorations made with many colored and shaped tile designs. It is likely possible to make glazes for these projects as well. They would take a huge amount of space and even more time and energy to create.
Medieval tiles are often quite thick and meaty in feel and appearance.
This lends problems with drying time and loss when firing. Don't be fooled by modern tile which makes use of automated production lines and engineered clay bodies. Every indication given shows that there was not a high amount of tinkering with the native lowland English clay. This means that firing the kilns must have been a highly skilled trade. They didn't have temperature cones either, and had to have judged temperature by sight alone.