std::vector<color_t> palette(const color_range& cr)
{
    std::vector<color_t> temp, res;
    std::set<color_t> clist;

    // Use blue to make master set of possible colors
    for(int i = 255; i != 0; i--) {
        int j = 255 - i;

        uint32_t rgb = i;
        temp.push_back(color_t::from_rgba_bytes(rgb));

        rgb = (j << 16) + (j << 8) + 255;
        temp.push_back(color_t::from_rgba_bytes(rgb));
    }

    // Use recolor function to generate list of possible colors.
    // Could use a special function, would be more efficient, but harder to maintain.
    std::map<color_t, color_t> cmap = recolor_range(cr, temp);
    for(const auto& cm : cmap) {
        clist.insert(cm.second);
    }

    res.push_back(cmap[255]);

    for(const auto& cs : clist) {
        if(cs != res[0] && cs != 0 && cs != {255, 255, 255}) {
            res.push_back(cs);
        }
    }

    return res;
}