how can I hide a color swatch image for configurable product that doesn't have a product image. How must I edit this file -> catalog_product_view_type_options_configurable.phtml to achieve this?
For hiding the color swatch file you need to edit the file app\design\frontend\rwd\default\template\configurableswatches\catalog\product\view\type\options\configurable\swatches.phtml
In this file, first you check that whether product have a product image or not and if product image does not exist, you can skip the swatch options in that loop through continue statement
And if you want to hide swatch option from product creation page then you need to make changes in getJsonConfig function in app\code\core\Mage\Catalog \Block\Product\View\Type\Configurable.php