I really like the idea of an orange ward (this makes me very happy, because rainbows).
(Also, pardon me for just shooting ideas down, but I think I'm better at that... Sorry :( )
One of the annoying things about this is that this requires people to keep a possible second slot open to allow the placing of an orange ward. While it's not too clunky, it is annoying to want to place a ward and find that you can't buy it because late game builds. Also, if you wanted to hold two, that extra ward is taking up a valuable spot that could be put towards another item.
I'm also not so sure about the proposed Sustain Ward properties, or any of the other alternatives.
For Pika's sustain ward, a Sweeper Trinket still counters it pretty handily; it'd do well to place this Sustain Ward near high priority objectives (i.e. Baron, Dragon), but any team who uses a sweeper in its area will probably take it out. What incentive does it give to the individual to not buy two Stealth Wards and instead buy a sustain? You get an extra four minutes of sight, true, but when it gets killed, you can just place another Stealth Ward instead of a Sustain. Ultimately, I'd rather have more Stealth Wards that I can place more frequently to move around rather than a Sustain Ward that I must keep stationary.
I also don't like the "safety passive" that Emmy mentioned, mostly because it's very easy to wobble between "too punishing" and "not punishing enough". There might be a "sweet spot", but it'd be incredibly hard to find; also, what would happen with life steal? In an implausible case, an ADC might actually be able to gain health from finding it, which would negate the consideration of the passive. Even in more plausible cases, one could easily negate the damage from a Safety Ward simply by finding some poor wraith and leeching away its health. Not to mention the deletion of health bars early game (140 damage? That chunks HARD :( )
A "blue trinket" type ward like Steelflame mentioned that has a large cast range could just as easily be emulated by the blue trinket; if I wanted to check Dragon, I'd just buy the blue trinket and save myself the gold. It'd only be seriously considered by supports and maybe junglers and ADCs (if they even feel like parting with their hard-earned gold :P ). Not like vision wards are really bought anyway, but that’s a concern that goes more into player mentality.
A “marking ward” like Iron Spatula mentioned is essentially like a vision ward. The benefit of marking champions that walk by is minimal; if you note the direction that an enemy is going, you can probably guess where they’re going as well. See Lee Sin on a pink going towards bot? Chances are he’s ganking bot. Fizz just showed at upper river and your blue is up? He might be going for a steal. So why not just buy the vision ward instead and save yourself 50 gold?
Despite all my hating (I’M SORRY I’M SORRY), it’d be really really cool to see a new ward make its debut. What I think would be cool would be some type of “pet ward” (PORO WARD PLS RITO) that a user would be able to control remotely for about ten seconds or so, much like a Tibbers, LB mirror image or an Ori ball. There’d be problems with early game jungles (Think Lee Sin is doing my red? Lemme just send my poro to scout it out) and also making chases much easier (GO PORO FIND THEM), but it’d be super cool, and also give the player a more active type of input.
Thanks for reading! I like this discussion :)