Selecting proper tiles for the floor in the hall
Firstly, make sure you buy a tile that is sold as a "floor tile". Some tiles are only suitable for walls (sold as "wall tiles") and won't survive the abrasion caused by being walked on. Most tiles are sold as "wall/floor tiles" and are suitable for either.


Colour. Go for whatever you fancy. This is basically a cosmetic decision. More expensive tiles should be less likely to stain, but it's difficult to know.
Filling. I assume you mean Grout? I.e. the thing that fills in between the tiles. Again this is mostly a cosmetic decision. But in terms of staining, grout is in general less durable than tile. A light grout on the floor is likely to darken over time. This may be an issue, as it'd discolour more in the more highly trafficked areas.
Size. Mainly cosmetic, but there are other considerations.


If your floor is deliberately not flat (mainly applies to shower cubicle floors rather than hallways) then smaller tiles can follow the curve much more easily than big ones.
If your floor is unintentionally not flat then big tiles require more care to lay well (a small angle change due to an imperfection, when extended over a long tile becomes a big vertical change, meaning adjacent tiles don't meet each other properly. This can be avoided by proper preparation before tiling.)
A good tiler should make sure that there is adhesive supporting the whole tile. Poor tilers who only dab adhesive onto part of the tile risk the unadhesived part being unsupported, leading to cracking when the unsupported part is loaded. With bigger distances on bigger tiles, this could be more of a problem. But, as said, with a good tiler it wouldn't be an issue anyway.

Format/ pattern of tile shape. Completely cosmetic.
Texture. If you buy perfectly smooth tiles, then any imperfection in tile laying is more obvious. If you have a bumpier tile, then imperfections in laying are less obvious. Also a smooth shiny tile shows up scratches, whereas a rough bumpy tile will tend to hide them.
Pricing. Your guess is as good as mine. Across every product of any type I've ever bought, I've hoped that more money means better quality. But it doesn't. Sure, there's some correlation, but it's impossible for me to say that because product A costs X times what product B costs that it'll last for Y times as long.