Cinnamons over here in the US are often called Browns and vice versa, (and some closely resemble a dark Buff Dundotte), depending on the breeder you buy them from and what
they call them. My Hens are usually darker than the males, and they all have a tendancy to change colors throughout the year as they go thru each molt.
Red eyes are not common among any Guinea Fowl in the US, in any color that I know of.
Here are some different examples/variations of Cinnamons and Browns I have in my flocks (I refer to the lighter birds as Cinnamons, the darker birds as Browns). As keets they are very similar in color and markings, maybe just a slight difference in the color shade, but as they feather out the Cinnamons get light feathers coming in and the Browns pretty much stay brown. None have red eyes
Cinnamons, Hen on top, male on bottom:
All are Brown Hens in these last 3 pics:
Male Buff Dundotte just for comparison: