First off, lets be clear, NO maker warranties their guns for anything above SAAMI standard.
We used to have "Ruger Only" loads, but then we used to have only ONE Ruger to shoot those loads in. Today, its different.
Tier I,II,III can get confusing, and is not something recognized by gun makers, officially.
Colts, and clones are good for the standard SAAMI approved loads (now being called "tier I"). EVERYTHING is good for "Tier I".
Your gun MAY be able to handle stronger loads, but there is NO official sanction, so you are on your own. CAREFUL load work up can show you where the safe stopping point is. Less than careful load work up can show you where the safe stopping point WAS!.
My personal standard "heavy" .45 Colt load is a 250grSWC and 10gr Unique. This is the listed MAX in all the old books for a Colt SAA. Well below the top end a Ruger Blackhawk .45 Colt can handle, it is not uncomfortable to shoot, does nearly 1100fps from my 7.5", and is accurate in my guns.
I don't know for certain, but it ought to also be safe in the DA .45Colt guns, although it is likely also a max load for them. Again, one has to CAREFULLY determine what your individual gun will take.
Remember, when you go beyond SAAMI specs, you are "off the map" and while other people's experiences can be a guideline, the "rules" are dependent on what your gun actually does.
Tread cautiously when exploring off the map, there be dragons here!!!