[Katae]

@maven

Forgive me, I haven't coded Lua for over a year and I'm doing this on my phone. But perhaps something along these lines?

function border(parent, color)
  return {
      name = parent .. "_border",
      parent = parent,
      anchor_to = "TOP",
      bg_color = color or "CLASS",
      bg_alpha = 1,
      width = "100%",
      height = "100%",
      strata = "BACKGROUND",
      level = 4,
      inset = -1
  }
end
lpanels:CreateLayout("Minimap_border", border("Minimap"))

Should use "CLASS" if you omit the color parameter.