Well... My theory for last evos...
Fennekin
Fire/Dark
Since Fennec foxes are nocturnal animals, I can clearly see a cuadrupedal, glammazonic, flames-themed fox, with this escense of mystery and eleganza that we can see puoring out Fennekin's ear fluffs (lol) about color schemes, I can see more red, light black, intense orange and some white...
Chespin
Grass/Steel
Parting from the idea of a hard chestnut, and discharting Rock type, the "hardest" type I can think of is Steel, I can imagine a hard-shelled knight in its shiny green chestnut armor, with some advanced deffensive system on its back, in the shape of a porcupin's needle-back, but with glances of nature. not all steel types have to be metalic, sylver/gray or robotic like.. Mawhile, Lucario, HIRACHI... so... not that crazy for a Chestknight...
and... Froakie (my fav)
Water/Fighting
Gamakitchi, Gamatatsu? Naruto's huge sword-wielder toad? so.. apart from that reference, to me, Froakie will be Ninja themed, so Fighting type fits just fine.. Besides Froakie looks like one of those japanese thieves, with gloves, backpack and a knot in its nose, all I can extract from that its the speed, accuracy and lethalness... so... Ninja Toad to me Plee-s!!