Colo(u)rs are automatically assigned to layers in the Layers dialogue/window, but you can change the colour assignments if you want to.
To see the colours you’ve assigned, you need to select Color by Layer using the blunt arrow top right of the Layers window (on Mac, anyway). That will colour everything in the SU window according to the colours you have set up - automatically or custom.
You can’t associate patterns with layers. What you CAN (and should) do is make components of the different parts of your model, then you can use the Materials window to assign colours or patterns to the components or individual faces of components. (Or groups, but I rarely find a use for groups, even if there’s only one instance of a component in the model).
Please read the help and tutorials about using components, groups and layers in SU.
ALWAYS, ALWAYS leave Layer0 as the active layer while drawing (its radio button selected in the Layers window/tray). Not doing so leads to madness later when things go invisible for reasons you will find hard to fathom.
The normal simple workflow is
- draw something
- triple click what you’ve just drawn to select it all
- press the keyboard letter g to start the Component creation dialogue
- give the component a meaningful name
- select the component axis origin if the default (‘bottom left hand corner’) doesn’t suit you
- check that Replace selection with component is ticked
- click [Create component]
If you don’t use components or groups, everything you draw will stick together, and editing becomes a nightmare.