id |title|images_missing
13 |shoes| 0
14 |shirt| 0

id|product_id|color|size|image
1 |        13|red  |M   |0
2 |        13|red  |XL  |1
3 |        13|green|M   |0
3 |        13|green|S   |0

select p.id,p.title,count(1) images_missing
from products p
inner join
(select product_id,color,sum(image)
from variations
group by product_id,color
having sum(image)=0) as v
on p.id = v.product_id
group by p.id,p.title