Function getForColour

src/OpenLoco/src/Graphics/PaletteMap.cpp:197–214

    }

    std::optional<View> getForColour(ExtColour paletteId)
    {
        auto g1Index = getPaletteG1Index(paletteId);
        if (g1Index)
        {
            auto g1 = getG1Element(*g1Index);
            if (g1 != nullptr)
            {
                const size_t length = g1->width * g1->height;

                // Palette maps must be of 256 entries per row.
                assert((length % kDefaultSize) == 0);

                return View(std::span{ g1->offset, length });
            }
        }
        return std::nullopt;
    }

    std::optional<View> getForImage(const ImageId image)
    {