If a love color was ever created it would pretty much have to be coupled with a hate color. Good luck making cards for both of these colors that do not all sound forced or childish.
PseudoElements do not necessarily need to be coupled with opposing elements. See Mirror Quanta as an example. Also, some PseudoElement pairs don't always directly oppose each other.
I actually think the theme of Love is a pretty fun one to use for card design, and as Xeno said the mechanic is pretty creative. Just my 2 cents.
If you need a more serious alternative, "Mercy" or "Ally" could work.
However Love has the symptoms of an additional Element not the symptoms of a PseudoElement. (The difference is: You can collect Love quanta therefore there is a Love quanta pool. PseudoElements do not have quanta pools or quanta types though they can have cost types.)
Pseudoquanta (aka alternate quanta cost mechanic using existing quanta types) Example: Mirror, Priori
PesudoElement (aka set with a cohesive elemental theme but uses existing quanta types) Example: Void, Divine
NewElement (aka set with a cohesive elemental theme and a new quanta type) Example: Mind, Love