In your spreadsheet, go to tools, click script editor, and create a blank script.
Replace any text inside the script with this function.
function paintRed() {
// Gets the entire workbook
var ss = SpreadsheetApp.getActiveSpreadsheet();
// Gets the sheet you are concerned with
// Change Sheet1 to the name of your sheet
var sheet = ss.getSheetByName("Sheet1");
// First 6 cells of the first row
// Change to whatever you like
var rangeToPaint = sheet.getRange("A1:F1");
// Gets the number of the last row in the sheet
// that has anything in it
var lastRow = ss.getLastRow();
// If the sheet is blank, set the first 6 cells
// in the first row to white and end the function
if (lastRow < 1)
{
rangeToPaint.setBackground("white");
return;
}
// Gets column A and column C
var rangeColumnOne = sheet.getRange("A1:A"+lastRow.toString());
var rangeColumnTwo = sheet.getRange("C1:C"+lastRow.toString());
// Gets the length of column A and C
var column1Length = rangeColumnOne.getValues().toString().replace(/,/g,"").length;
var column2Length = rangeColumnTwo.getValues().toString().replace(/,/g,"").length;
// If column A is blank or column C is not blank,
// set the first 6 cells to white and stop the
// function
if ( column1Length < 1 || column2Length > 1 )
{
rangeToPaint.setBackground("white");
return;
}
// Otherwise, paint the first 6 cells red
rangeToPaint.setBackground("red");
}
You will need to change Sheet1 to whatever the name of your sheet is.
Then, while still in the script editor, click resources, 'current project triggers.'
Add a new trigger with 'Run' set to paintRed and Events set to 'From spreadsheet' 'On edit.'
You should be good to go.
Link to spreadsheet you can copy to your drive, then play with - https://docs.google.com/spreadsheet/ccc?key=0Ar6b2EOADTG7dGJOM0lEalhjd3pNOHNRNnBDOV8xRnc&usp=sharing