I never really got around to a serious discussion of design theory in relation to cycling kits but there must be a ...
a) thorough appreciation of the medium and the manner in which it presents itself
b) proper level of respect for each party in the transaction, namely the sponsor and the riders
c) positive tension between the inventive and the conservative in the application of colour theory
While the first two are universal, the third is a matter of personal taste. What we usually find with kits we don't like is that one or more of the above will have been breached in some way.
For example:

is very well designed by a strict reading of the criteria of (a) and (b) but for me it fails on (c) and thus somewhat hurts (b) with regard to the riders, even while it is part of the sponsor's corporate identity.
Another exercise is to remove the point of failure and re-examine. I'll do that now.
Brown FFSAsk most VR members and they'll tell you that their main Greipel with the

kit is the liberal employment of brown. On a cyclist, it looks like nothing more than sh*t-coloured anathema, hence the failure on (c) above.
So why on Earth did the company's corporate identity designers choose brown?
Well, I don't know for sure, but they certainly didn't have the cycling team in mind when they rebranded after the merger of AG2R (formerly known as "Association Générale de Retraite par Répartition", hence AG2R) and La Mondiale in mid-2009.
A wild guess is that, together with muted cyan, it all has to do with an analogy of earth and sky or water, elements of which we can be reasonably certain in this life while everything else is, as popular French singer Manu Chao memorably put it, a tombola.
It also happens that these colours are
complementary, which is key to our scientific perception of that which is 'beautiful' or 'harmonious', as you can see in this rough mockup...
But what if ... ?The kit would probably appeal to VR members moreso if it gave the riders a bit more dignity but, as the very first incarnation of the AG2R team shows us, that is not always straightforward with Vincent Lavenu who has proved down the years to be, at least in kit terms, some kind of inverted King Midas.
Here's Oleg Kozlitine modelling that famous farce:

And after suffering that humiliation, is it any wonder that a decade later he would be using U23 riders as drug runners for Cofidis?
So AG2R's corporate identity may be a fait accompli but there's no reason not to dabble with those colours and in particular that faecal brown.
Other harmonious colour relationships exist beyond complementary, so let's see if we can solve a problem like (c) just with the power of the simplest changes, swapping out
only the hue of stools and sticking to the rules of colour theory.
Compound colour relationships offer greater contrast but with some genuinely exciting possibilities. Consider an AG2R cyan's compounds:

The blues out left offer little contrast but that blood red is bordering on spectacular. Let's try that:

Not bad, is it?

Now for something
really radical.
Triadic colours:


Channelling T-Mobile a bit with that one. Or better, Koechli's ridiculously modern design classic from the 90s (also an insurance / pensions sponsor):

So there we are folks. I hope the above showed us that the

design is actually pretty sound. It's just that diarrhoetic brown that sends the whole thing down the toilet bowl.
And that was colour. Next time, if I can get my shiznit together, I might talk about geometry.