There have been some research activities in the past that deal with identical twins and the partners they select. Skipping past all the detail and to the point, it would appear that in humans, the selection of a partner is inherently random. Often the twin doesn't actually like the partner of the other twin.
This to me makes sense when you consider the 'three brain model' of neurophysiology. In that model, the human brain is made up of three 'layers'; the cerebellum that manages instinct, autonomic functions like keeping the heart beating and muscle control; the limbic system (reptilian brain) that manages emotions, and; the cerebral cortex (mammalian brain) which handles higher reasoning, abstracted problem solving etc. It is the cerebral cortex that is responsible for our sentience, but it is the cerebellum that is responsible for sexual attraction and drives.
So; what about your aliens? They can't have the same brain structure, surely? They evolved in completely different ways, right?
Well, actually we can expect a layered approach to brain development in aliens because their evolutionary model is going to have to deal with the same two problems that Earth based evolution had to deal with;
1) Nature prefers efficiency, therefore does not reward needlessly complex structures
2) You can't just put a species' brain function on hold for a thousand generations to redesign it for a more complex environment
Another way of putting this is that in the early stages of evolution, autonomic functions and muscle control are all you really need a brain to do, so evolution doesn't design something that can be extended beyond that to any great degree. As the need for emotions come into play, newer systems that operate differently but intrude on the neural process of the first evolve, then more and more.
Your aliens may only have a 2 brain model, they may have a 6 brain model. But, it's highly unlikely that they achieve sentience with a single brain construct so to speak.
This is important because sex is (to be blunt) a critical factor in very early evolutionary survival, but intelligence isn't. Therefore, it is safe to say that while intelligence may play a factor in mate selection later in the evolutionary ladder, it does not preclude the use of bright or large displays either. As such, intelligence isn't likely to impact display behaviours and plumage (to use a word that over-simplifies the display constructs that may evolve).
There is a single caveat to this; brains capable of intelligence are very resource intensive and therefore only evolve where this massive cost in energy results in a net benefit. In humans, the brain consumes around 25% of the energy intake of the average person, which in a simple instinctive fight or flight environment could be put to better use. This is also why beanies keep you warm in the snow; a lot of the heat loss in the human body occurs from heat radiating out of the head because of what the brain is doing.
Displays also require a lot of energy either to create (peacock feathers), display (blood flushing) or enact (dancing style presentations). As such, on some planets, the species may have to make a choice, evolutionarily speaking. It can either continue to present but limit neural development, or enhance neural development at the cost of display. To do the latter, displays of intelligence MUST be prioritised by their version of a cerebellum for mate attraction, otherwise the plumage will always out-do the mental display.
In any event, intelligence doesn't automatically override the plumage per se; ultimately if the energy cost of managing both is possible, it will happen but it is important to note that both have a large energy requirement that evolution has to somehow reconcile.