Sometimes it is possible to replace code with a table. A small piece of code will do what is in the table.
Sometimes it is possible to replace a library with a smaller library.
However, if you have a lot of different sequences for a ledstrip, then there is not much that can be done.
If you use the newest Arduino IDE, then the optimization for size and the "LTO" optimization are already turned on. That means the compiler can already put an incredible amount of code into the Arduino flash memory.
If you want more than "incredible", that is not possible.
Nevertheless, if you show your sketch and tell for which Arduino board it is, then we might help to reduce the code here and there and perhaps we can advice which parts can be removed.