Originally Posted by Codetapper
To make 16 colour sprites you must attach 2 sprites together using the attach bit.
AFAIK AGA defaults to normal 4 colour sprites like ECS, but you do get the added benefit of being able to pick your palette from any one of the 8 blocks of 32 colours. You can also choose between 35, 70 and 140ns sprites meaning you can have higher resolutions and up to 64 bits wide instead of 16 like OCS.
I have played around with this quite a bit, it seems the problem is with the fetch mode. The higher fetch modes restricts how you can use sprites by the looks of it (correct me if I'm wrong). This explains why my sprite only appeared in 3 colours despite using 15 colours initially to design it. Also you are restricted to using only 1 sprite, without adjusting the width of the display. So if I used a lower fetch mode I could use a 15-colour sprite.
Of course I could be talking rubbish but that's how I see it.