Updated to use ComputerCraft colours

**Bugs found:**
- Colour palette block's default is not something picked from list, it is static #ff0000 this should be addressed
- Generating the Lua code places a hex string for example `"#ff0000"` instead of either `colours.red` or `16384`
- [known] hovering over the colour the tooltip shows the rgb *[proposed fix]* perhaps have another key in the array of colours that specifies tooltip?