Magento – Magento 2: Multiple choice swatch attribute

Magento gives the support for what you need but it's kind of a long shot.
You are able to set a different source model to your dropdowns.
Let's take for example the attribute tax_class_id. It's a dropdown but it does not have the values stored in the database (tables eav_attribute_option and eav_attribute_option_value). The source model is tax/class_source_product that in a non-customized instance translates to class Mage_Tax_Model_Class_Source_Product.
In the case of tax_class_id the options shown in the dropdown are the result of Mage_Tax_Model_Class_Source_Product::getAllOptions().
You can create a custom extension with a custom model (or 3 - one for each attribute). Set those models to be the source model for your attributes and add your logic inside the getAllOptions() method. In this method you can get the values from a table or hard code them, even get them through an external API.
Your custom source models should extend Mage_Eav_Model_Entity_Attribute_Source_Abstract and should have the following methods:

• getAllOptions() - this is where the logic is. This should return an array of arrays. the array at the lower level should look like array('value'=>'SOME NUMBER HERE', 'label'=>'Label here');
• getOptionText() should be similar to the one in Mage_Tax_Model_Class_Source_Product
• toOptionArray() similar to the one in Mage_Tax_Model_Class_Source_Product.
• getFlatColums() similar to the one in Mage_Tax_Model_Class_Source_Product just change the column comment
• getFlatUpdateSelect() similar to the one in Mage_Tax_Model_Class_Source_Product

Check this for a small tutorial on how to add an attribute with custom options
Also follow how the source model for tax_class_id is made. It helps.

In the module the app/code/core/Mage/ConfigurableSwatches/Helper/Productlist.php is the helper which determines which _swatchAttributeId should be used.

You could extend this module and rewrite the helper. Rewrite the getSwatchAttributeId function and do you own magic.

You could

• just add some id logic, Mage::registry('current_category')->getCategoryId()
• add a custom option for a category which you can set per category
• read it from the attributeset used for the first product