LightBurn defaults to working in wireframe as it is easier to see all shapes that can affect the output. We do provide Filled-rendering as well, but things can get obscured if they fall behind another shape or object, and become more difficult to select, which can be confusing if not expected.
LightBurn uses your original shape color to automatically assign the shapes of that color to a layer. This is intended to help speed cut-setting assignment when leveraged in your workflows. When importing art, LightBurn will do a ‘best match’ to our published color pallet, which I share below, and place each shape on the corresponding layer.