Here are the other two paintings:

>! [![enter image description here][1]][1]<br><br>[![enter image description here][2]][2]

The shown image in the question contains

>! The evolutions of all grass starter pokemon from generations 1 through 5: <pre><code>Bulbasaur,Ivysaur,Venusaur,Chikorita,Bayleef,Meganium,Treecko,Grovyle,Sceptile,Turtwig,Grotle,Torterra,Snivy,Servine,Serperior</code></pre>

because

>! each row has the color palette of the corresponding pokemon, but treating the RGB value as BGR, which means the shown image doesn't display their "true" colors.

So the other 2 paintings contain

>! Fire and Water Starters from generation 1-5:<br><br>Fire:<br>`Charmander,Charmeleon,Charizard,Cyndaquil,Quilava,Typhlosion,Torchic,Combusken,Blaziken,Chimchar,Monferno,Infernape,Tepig,Pignite,Emboar`<br><br>Water:<br>`Squirtle,Wartortle,Blastoise,Totodile,Croconaw,Feraligatr,Mudkip,Marshtomp,Swampert,Piplup,Prinplup,Empoleon,Oshawott,Dewott,Samurott`

Story elements:

>! It's called Evolution because the image portrays pokemon evolutions.<br><br>She was going to give me a starter pokemon for the beginning of my journey.<br><br>The device is a pokedex.<br><br>The assistant professor is probably Bianca, because this story seems to play out in Pokemon Black/White, Leonora's (gym leader) hometown being Nacrene City, which has a museum and has some vague connection to an ancient festival.<br><br>The forest is Pinwheel Forest, right near the city, where she would like to research pokemon!<br><br>Not sure about the time and place yet.

Fun Stuff:
>! Here are the "unaltered" two paintings, i.e. in RGB:<br><br>[![enter image description here][3]][3]<br><br>[![enter image description here][4]][4]


  [1]: https://i.sstatic.net/kEReH7vb.png
  [2]: https://i.sstatic.net/cvsMLJgY.png
  [3]: https://i.sstatic.net/tronlXUy.png
  [4]: https://i.sstatic.net/GPJhoTrQ.png