The colour from the spices can give us a hint as to the proportions. With 12 ingredients, if they were in equal proportions you'd have 8% turmeric which is already going to do quite a bit to make it yellow.
But it won't have equal proportions: The cayenne and paprika would make it come out red or at least deep orange if so, and the nutmeg flavour would be too strong (possibly also the cardamom and black pepper.
You could get to about 16% turmeric if you had equal proportions of the top 6 ingredients, and tiny amounts of the remaining 6. Reality will be somewhere in between. I would suggest starting from 1 teaspoon of each ingredient (bought in ground form) down to the turmeric, and half a teaspoon of the ingredients after that, or maybe a little less. If it looks too red, add more of all the top 6.
Then use it and taste the result.
You should choose whether to use hot or mild ("sweet") paprika based on whether you want much chilli heat; the cayenne will have some already.