Guys, i've just been having a bit of a play with the tactical squares graphic, if you want to try a much higher contrast graphic, give this a go. Download this file:
And save it to your \FE Legendary Heroes\Gfx folder (normally the full path would be something like C:\Program Files (x86)\Steam\steamapps\common\FE Legendary Heroes\Gfx).
Just maybe backup the original TileSelectionTexture_Tactical.dds file first (rename it).
This changes the tactical movement graphic to a similar but much more visible version. Might be the sort of thing you're after if you have a hard time seeing the default one.