Parameter: Select > background color OR gradient

I’m trying to set up a background color so that it can be one of 2 linear gradients or 2 solid colors. the solid colors work, but I can’t figure out a trick to get the gradients to work.

any suggestions? I need this because of how the component sits between two other components. you can see in the screenshot how it’s opposite in this case.

  "BkGrndColor" : {
    "type"    : "select",
    "label"   : "Background Color",
    "initial" : "white2hard-grey",
    "options" : [
      { "value" : "background-image: linear-gradient( to bottom,#c0c2cc 50%,#f5f5f5 50.01%)", "label" : "code" },
      { "value" : "{{ global.color({ 'id':'white2hard-grey'}) }}", "label" : "White / Grey" },
      { "value" : "{{ global.color({ 'id':'hard-grey2white'}) }}", "label" : "Grey / White" },
      { "value" : "{{ global.color({ 'id':'liberty-atmospheric-white'}) }}", "label" : "Atmospheric White" },
      { "value" : "{{ global.color({ 'id':'white'}) }}", "label" : "White" }
    ]
  }