I think they're maybe a bit garish in player-colours. Could perhaps just the bottom rails, or top rails, be player coloured, and the rest a battleship grey? (I'd say red-oxide but that maybe a player colour!). I mean, FGW may have purple trains but their bridges are definitely not!
Another suggestion - we need a flat bridge - that is a bridge for rail (and road) to cross water on-the-level. The ideal might be that a swing bridge (or bascule bridge) evolves into a more modern interpretation at some c20th date. A swing bridge needs an island, of course, I can't recall if river traffic works like roads, left and right sides, or not...
Swing Bridge, Norfolk (there's a nice one in Newcastle too, but it's a bit bigger).
I recall being told it's not possible to vary a crossing type with a timeline, but presumably it's done with level crossings - gates become barriers at some point I assume? If so, in pak.128 is a lift bridge like the kingsferry bridge on the isle of sheppy. We could use that as the later one?
The alternative, of course, perfectly realistic, is to have a single flat crossing, which does not allow water craft to pass - that is, a fixed short bridge which deliberately obstructs navigation. Which would force the use of 'better', higher bridges to cross water - the sort of dilemma which faced real engineers and led, for example, the GWR not to build a railway line to Dartmouth (since they'd have needed another Saltash-type bridge) and go to Kingswear instead.
e.g. a bridge like this: