Matching two variants

I'm having trouble reflecting physical stock to variants available to customers. 

Example:

I am trying to list personalised pyjamas. They are available in:

red, green, pink, grey

Red are only available in 1-2 years

Green, pink and grey are available in 1-2 years, 4-5 years, 6-7 years

Drop down box 1 is for the colour and drop down box 2 is for the size. Despite the fact that red colour is selected, all of the above sizes come up in drop down box 2, even though they are not in stock. Also, message 'out of stock' does not come up, even though I have it switched on in settings. All that happens is a message that product can't be added to shopping cart - very frustrating and confusing for customers 
Is there another template where maybe subcategories are available? This would allow me to have a category for pyjamas, then sub category for red, green etc and I can do size variations there? 

 Any help would be appreciated :)