Class GradientCondition

// Logs all the information inside gradient conditional format rules on a sheet.
// The below snippet assumes all colors have ColorType.RGB.
var sheet = SpreadsheetApp.getActiveSheet();
var rules = sheet.getConditionalFormatRules();
for (int i = 0; i < rules.length; i++) {
  var gradient = rules[i].getGradientCondition();
  Logger.log("The conditional format gradient information for rule %d:\n
    MinColor %s, MinType %s, MinValue %s, \n
    MidColor %s, MidType %s, MidValue %s, \n
    MaxColor %s, MaxType %s, MaxValue %s \n", i,
    gradient.getMinColorObject().asRgbColor().asHexString(),
    gradient.getMinType(), gradient.getMinValue(),
    gradient.getMidColorObject().asRgbColor().asHexString(),
    gradient.getMidType(), gradient.getMidValue(),
    gradient.getMaxColorObject().asRgbColor().asHexString(),
    gradient.getMaxType(), gradient.getMaxValue());
}