That is a cool wrasse isn't it? Not to hijack but you're actually one of 3 people on our list for another male Paracheilinus carpenteri, I feel I should mention that any male can change into an "alpha" if it is the only male in a group of females, the trick to mitigating aggression is adding them all simultaneously so they can establish a pecking order for the available territory, and one fish doesn't claim the whole tank as its own, helps a lot if they're the first fish to enter a system as well. It's only rare to find such a nice male in a store or through a wholesaler because there's only one at a time in any given locality, alpha male isn't even really a good term for this condition because of it's close association with canine social structure, males are territorial no matter what which is why they're harder to come by, but when they get into breeding mode, that is to say when they are comfortable and don't feel threatened by any conspecifics, they get that intensified coloration and flash their fins much more, which has led to the trade nickname "alpha" for fish that already display this behavior on arrival. The best way to induce this change is to keep a single male in a large tank with at least 2 females. Make sure each fish has the opportinity to stake out it's own territory, and your male should come into it's own before too long. The females are not necessary to induce the change, but there's nothing that convinces me they wouldn't help the process along, and it opens up a slim possibility for them to spawn in your tank with an appropriate diet.
My real point here is you are liable to be waiting a very long time if you want another male that looks like the one we just got in, but if you would rather work with a fish to allow it turn into a displaying male, you can get your fish much faster.