Birds of a feather

It is an interestring observation that the male of a bird species
often is the most colourful one, whilst the female is quite plaine.

I supposit that we can come up with various evolutionary theories on that,
as the male must impress the female before she is moved to mate with her choice.  Female choice, is what we are seeing being expressed by many species of birds.  The exotic peacock feather displays, are a result of many
countless sexual selections.

Which then brings us to come up with a theory of why it sometimes appears to be the opposite, in human culture.  Culture mind you, as women seem to be the species that doll themselves up more often them men, who tend to show up to work with more utilitarian clothing.   If we strip away the clothing, one might ask, is the male still the more appealing creature?  

For me it is hard to say. In addition to that, we must also take cognizants of female infanticide, as practiced in the ancient cultures of China and India, and perhaps in other lands.

What kind of theory could explain the cultural success of female infanticide during times of population stress? And is the art of applying makeup within the female species possibly a modern adaptation of female infanticide?

I admit I have just made what would seem to be some far afield comments!
Oh, where to begin, where to begin.  OK, let us together do a thought experiment on this.    

A Drought has come.    
The crops have failed.
There is little to eat.

for what ever personal reason a mother, and the
people around her, are driven by, it may be an unquestioned
'tradition', it may be a collective jealousy of the women, who dont
appreciate the extra competition this little girl child will present in 13 years,

The girl babies are discarded, but the boy babies are allowed to live.
in this theoretical time of stress.
Theoretical thought experiment.
Now with the quite powerful forces of haman's desire to
mate, the reduction of the female numbers, would,
in a brutal way,
eventually reduce the number of births.
The remaining males, would be available to
carry out work, to improve the situation.
If the female has much to say about who they mate with,
then they would then have a larger pool of men to pick from,
thus picking the most fit, and seductive of them.

So at this stage of our thought experiment, we could start forming the opinion that female infanticide during times of population stress,
would reduce the production of babies, and also permit the remaining
females to have a larger pool of males to choose from, thus improving the
offspring for the next generation.

Now this may seem to make sense, but in modern society, a new belief has been adopted, where it is viewed as unconscionable to kill babies period.
So what to do when times get tough?
Well in modern social behaviour, it is frowned upon to have relations
outside of wedlock, and so there is now a pool of hopeful virgins under this 'new' system.  Also in this system, is the belief that the male must become 'established' within the society, to be able to support the woman, and her subsequent stream of offspring.  He then approaches the pool of available women to make his pick.  

Which then provides an understandable reason why a woman will doll herself up, so as to stand out from the others.
In times of famine, the social norms of wanting to mate are overridden by proper social behavior, so the population does not explode, even though there is an ample supply of waiting women, but a reduced supply of men who have figured out how to 'establish' themselves, as their environmental forces drive things.

War fits nicely into this new social order, as the excess men can be killed off, and the spoils go the victors, who then can take the excess females as slaves, and are allowed to mate with them, along with their newly acquired spoils.