Create diverging color scheme for gt_color_box from GT package

Question

I would like to modify the palette of the gt_color_box() function from the R package GT such that It can accommodate two scales:

1. Numbers below and equal to zero (color1, color2)
2. Numbers above 0 (color3, color 4)

The code for the function is below and I'm unclear on how to modify it. Any help would be greatly appreciated.

gt_color_box <- function(gt_object, columns, palette = NULL, ..., domain = NULL,
                         width = 70, font_weight = "bold") {
  stopifnot("Table must be of class 'gt_tbl'" = "gt_tbl" %in% class(gt_object))

  color_boxes <- function(x) {
    stopifnot("Error: 'domain' must be specified." = !is.null(domain))

    if (length(palette) == 1) {
      if (grepl(x = palette, pattern = "::", fixed = TRUE)) {
        palette <- paletteer::paletteer_d(
          palette = palette
        ) %>% as.character()
      } else {
        palette <- palette
      }
    } else if (is.null(palette)) {
      palette <- c(
        "#762a83", "#af8dc3", "#e7d4e8", "#f7f7f7",
        "#d9f0d3", "#7fbf7b", "#1b7837"
      )
    } else {
      palette <- palette
    }

    if (palette[1] == "pff") palette <- c("#cd2624", "#fd9701", "#ffd000", "#3bae24", "#0c5ea0")

    colors <- scales::col_numeric(palette = palette, domain = domain)(x)

    background_col <- scales::alpha(colors, alpha = 0.2)

    div(
      div(
        style = paste0(
          glue::glue(
            "height: 20px;width:{width}px; background-color: {background_col};"
          ),
          "border-radius:5px;)"
        ),
        div(
          style = paste0(
            glue::glue("height: 13px;width: 13px;background-color: {colors};"),
            "display: inline-block;border-radius:4px;float:left;",
            "position:relative;top:17%;left:6%;" # top 12%-15%
          )
        ),
        div(
          scales::label_number(...)(x),
          style = paste0(
            glue::glue("display: inline-block;float:right;line-height:20px; font-weight: {font_weight};"),
            "padding: 0px 2.5px;"
          )
        )
      )
    ) %>%
      as.character() %>%
      html()
  }

  text_transform(
    gt_object,
    locations = cells_body({{ columns }}),
    fn = function(x) {
      x <- as.double(x)
      lapply(x, color_boxes)
    }
  )
}