With my Canon 430EX III came a tungsten filter than neatly clips on to the flash head. However, it seems this is the only filter available.
I notice the Canon 600EX series comes with a clear filter holder that allows you to place a pre-cut gel inside.
Is there a clear filter-holder available to the 430EX III? Perhaps from a third-party? I've checked online extensively and can't find anything, so I'm assuming such a thing isn't available. And, I can't see anyway to make or adapt one. So, I figure it's back to sticking velcro strips to the flash head. It's a shame as a clear filter holder would be a neat solution.