if you can’t find a roller, on top of your base coat, you can spatter and drag the necessary colours to get a really good facsimile. Best if you can do each colour separately, and work the floor in manageable sections.
I have made this type of roller before. We used the core of a paper roll, and adhered dots and strips of thick felt and 3M scrub pads. The core fit perfectly over a standard roller cover. The adhesive was Super 88 food adhesive, but I have also used contact cement, the flammable kind.
We rolled it onto the wet base coat and dragged through it. Worked like a charm.