http://bulbapedia.bulbagarden.net/wiki/List_of_Pok%C3%A9mon_by_color
Red:
Edit (31.12.2019): Added Gen VIII additions.
Pokémon that change Color after Evolution:
Red:- Magikarp->Gyarados(Blue)
- Yanma->Yanmega(Green)
- Wurmple->Silcoon(White)->Beautifly(Yellow)/->Cascoon(Purple)->Dustox(Green)
- Carvanha->Sharpedo(Blue)
- Venipede->Whirlipede(Gray)->Scolipede(Red)
- Oddish->Gloom->Vileplume(Red)/Bellossom(Green)
- Dratini->Dragonair->Dragonite(Yellow)
- Phanpy->Donphan(Gray)
- Meditite->Medicham(Red)
- Clamperl->Gorebyss(Pink)
- Mantyke->Mantine(Purple)
- Ducklett->Swanna(White)
- Karrablast->Escavalier(Gray)
- Elgyem->Beheeyem(Brown)
- Bagon->Shelgon(White)->Salamence(Blue)
- Poliwag->Poliwhirl->Politoed(Green)
- Cosmog->Cosmoem-> Solgaleo(White)/Lunala(Purple)
- Rookidee->Corvisquire->Corviknight (Purple)
- Blipbug->Dottler (Yellow)->Orbeetle (Red)
- Psyduck->Golduck(Blue)
- Makuhita->Hariyama(Brown)
- Numel->Camerupt(Red)
- Chingling->Chimecho(Blue)
- Sewaddle->Swadloon(Green)->Leavanny(Yellow)
- Scraggy->Scrafty(Red)
- Deerling->Sawsbuck(Brown)
- Mienfoo->Mienshao(Purple)
- Cufant->Copperajah (Green)
- Galarian Meowth->Perrserker (Brown)
- Caterpie->Metapod->Butterfree(White)
- Scyther->Scizor(Red)
- Spinarak->Ariados(Red)
- Larvitar->Pupitar(Gray)->Tyranitar(Green)
- Gulpin->Swalot(Purple)
- Axew->Fraxure->Haxorus(Yellow)
- Electrike->Manectric(Yellow)
- Yamask->Cofagrigus(Yellow)
- Spoink->Grumpig(Purple)
- Galarian Yamask->Runerigus (Gray)
- Weedle->Kakuna(Yellow)->Beedrill(Yellow)
- Vulpix->Ninetales(Yellow)
- Staryu->Starmie(Purple)
- Shroomish->Breloom(Green)
- Slakoth->Vigoroth(White)->Slaking(Brown)
- Trapinch->Vibrava(Green)->Flygon(Green)
- Baltoy->Claydol(Black)
- Feebas->Milotic(Pink)
- Lillipup->Herdier(Gray)->Stoutland(Gray)
- Sandile->Krokorok->Krookodile(Red)
- Tyrunt->Tyrantrum(Red)
- Zigzagoon->Linoone(White)
- Eevee->Flareon(Red)/Vaporeon(Blue)/Espeon(Purple)/Umbreon(Black)/Leafeon(Green)/Glaceon(Blue)/Jolteon(Yellow)/Sylveon(Pink)/Flareon(Red)
- Clobbopus->Grapploct (Blue)
- Galarian Farfetch'd->Sirfetch'd (White)
- Rattata->Raticate(Brown)
- Tyrogue->Hitmonchan/Hitmontop/Hitmonlee(Brown)
- Lileep->Cradily(Green)
- Crabrawler->Crabominable(White)
- Misdreavus->Mismagius(Purple)
- Remoraid->Octillery(Red)
- Barboach->Whiscash(Blue)
- Timburr->Gurdurr->Conkeldurr(Brown)
- Nincada->Ninjask(Yellow)/Shedinja(Brown)
- Espurr->Meowstic(White)
- Pineco->Forretress(Red)
- Snorunt->Froslass(White)
- Grubbin->Charjabug(Green)->Vikavolt(Blue)
- Mareep->Flaaffy(Pink)->Ampharos(Yellow)
- Wingull->Pelipper(Yellow)
- Rufflet->Braviary(Red)
- Scorbunny->Raboot (Gray)->Cinderace (White)
- Galarian Zigzagoon->Galarian Linoone->Obstagoon(Gray)
- Exeggcute->Exeggutor(Green)
- Porygon->Porygon2(Red)->Porygon-Z(Red)
- Hoppip->Skiploom(Green)-Jumpluff(Blue)
- Snubbull->Granbull(Purple)
- Smoochum->Jynx(Red)
- Skitty->Delcatty(Purple)
- Whismur->Loudred(Blue)->Exploud(Blue)
- Mime Jr.->Galarian Mr. Mime (White)->Mr. Rime(Purple)
- Impidimp->Morgrem->Grimmsnarl (Purple)
Pokémon that keep their Color through Evolution:
Red:
- Charmander->->Charmeleon->Charizard
- Paras->Parasect
- Krabby->Kingler
- Voltorb->Electrode
- Goldeen->Seaking
- Magby->Magmar->Magmortar
- Ledyba->Ledian
- Slugma->Magcargo
- Torchic->Combusken->Blaziken
- Corphish->Crawdaunt
- Kricketot->Kricketune
- Tepig->Pignite->Emboar
- Pansear->Simisear
- Darumaka->Darmanitan
- Dwebble->Crustle
- Shelmet->Accelgor
- Pawniard->Bisharp
- Fennekin->Braixen->Delphox
- Fletchling->Fletchinder->Talonflame
- Litten->Torracat->Incineroar
- Sizzlipede->Centiskorch
- Squirtle->Wartortle->Blastoise
- Nidoran Female->Nidorina->Nidoqueen
- Poliwag->Poliwhirl->Poliwrath
- Tentacool ->Tentacruel
- Tangela->Tangrowth
- Horsea->Seadra->Kingdra
- Omanyte->Omastar
- Totodile->Croconaw->Feraligatr
- Chinchou->Lanturn
- Azurill->Marill->Azumarill
- Wooper->Quagsire
- Wobbuffet->Wynaut
- Mudkip->Marshtomp->Swampert
- Taillow->Swellow
- Surskit->Masquerain
- Wailmer->Wailord
- Swablu->Altaria
- Spheal->Sealeo->Walrein
- Clamperl->Huntail
- Beldum->Metang->Metagross
- Piplup->Prinplup->Empoleon
- Shinx->Luxio->Luxray
- Cranidos->Rampardos
- Gible->Gabite->Garchomp
- Riolu->Lucario
- Croagunk->Toxicroak
- Finneon->Lumineon
- Oshawott->Dewott->Samurott
- Panpour->Simipour
- Roggenrola->Boldore->Gigalith Gigalith
- Woobat->Swoobat
- Tympole->Palpitoad->Seismitoad
- Tirtouga->Carracosta
- Deino-> Zweilous->Hydreigon
- Froakie->Frogadier->Greninja
- Inkay->Malamar
- Clauncher->Clawitzer
- Amaura->Aurorus
- Bergmite->Avalugg
- Popplio->Brionne->Primarina
- Mareanie->Toxapex
- Sobble->Drizzile->Inteleon
- Pichu->Pikachu->Raichu
- Sandshrew->Sandslash
- Meowth->Persian
- Ponyta->Rapidash
- Drowzee->Hypno
- Elekid->Electabuzz->Electivire
- Cyndaquil->Quilava->Typhlosion
- Sunkern->Sunflora
- Combee->Vespiquen
- Archen->Archeops
- Joltik->Galvantula
- Helioptile ->Heliolisk
- Cutiefly->Ribombee
- Yamper->Boltund
- Bulbasaur->Ivysaur ->Venusaur
- Bellsprout->Weepinbell->Victreebel
- Chikorita->Bayleef->Meganium
- Natu->Xatu
- Treecko->Grovyle->Sceptile
- Lotad->Lombre->Ludicolo
- Budew->Roselia->Roserade
- Cacnea->Cacturne
- Turtwig->Grotle->Torterra
- Bronzor->Bronzong
- Snivy->Servine->Serperior
- Pansage->Simisage
- Cottonee->Whimsicott
- Petilil->Lilligant
- Trubbish->Garbodor
- Solosis->Duosion->Reuniclus
- Golett->Golurk
- Chespin->Quilladin->Chesnaught
- Dewpider->Araquanid
- Grookey->Thwackey->Rillaboom
- Gossifleur->Eldegoss
- Chewtle->Drednaw
- Applin->Flapple/Appletun
- Dreepy->Drakloak->Dragapult
- Munchlax->Snorlax
- Murkrow->Honchkrow
- Sneasel->Weavile
- Houndour->Houndoom
- Shuppet->Banette
- Duskull->Dusclops->Dusknoir
- Blitzle->Zebstrika
- Scatterbug->Spewpa->Vivillon
- Pikipek->Trumbeak->Toucannon
- Salandit->Salazzle
- Rolycoly->Carkol->Coalossal
- Pidgey->Pidgeotto->Pidgeot
- Spearow->Fearow
- Diglett->Dugtrio
- Mankey->Primeape
- Growlithe->Arcanine
- Abra->Kadabra->Alakazam
- Geodude->Graveler->Golem
- Doduo->Dodrio
- Cubone->Marowak
- Kabuto->Kabutops
- Sentret->Furret
- Hoothoot->Noctowl
- Bonsly->Sudowoodo
- Teddiursa->Ursaring
- Swinub->Piloswine->Mamoswine
- Seedot->Nuzleaf->Shiftry
- Chimchar->Monferno->Infernape
- Starly->Staravia->Staraptor
- Bidoof->Bibarel
- Buizel->Floatzel
- Buneary->Lopunny
- Hippopotas->Hippowdon
- Patrat->Watchog
- Vullaby->Mandibuzz
- Bunnelby ->Diggersby
- Litleo->Pyroar
- Skiddo->Gogoat
- Honedge->Doublade->Aegislash
- Binacle->Barbaracle
- Skrelp->Dragalge
- Phantump->Trevenant
- Pumpkaboo->Gourgeist
- Rowlet->Dartrix->Decidueye
- Yungoos->Gumshoos
- Rockruff->Lycanroc
- Mudbray->Mudsdale
- Sandygast->Pallosand
- Skwovet->Greedent
- Nickit->Thievul
- Arrokuda->Barraskewda
- Ekans->Arbok
- Nidoran♂->Nidorino->Nidoking
- Zubat->Golbat->Crobat
- Venonat->Venomoth
- Grimer-> Muk
- Shellder->Cloyster
- Gastly->Haunter->Gengar
- Koffing->Weezing
- Aipom->Ambipom
- Gligar->Gliscor
- Shellos->Gastrodon
- Drifloon->Drifblim
- Stunky->Skuntank
- Skorupi->Drapion
- Purrloin->Liepard
- Gothita->Gothorita->Gothitelle
- Goomy->Sliggoo->Goodra
- Noibat->Noivern
- Morelull->Shiinotic
- Bounsweet->Steenee->Tsareena
- Toxel->Toxtricity
- Sinistea->Polteageist
- Machop->Machoke->Machamp
- Magnemite->Magneton->Magnezone
- Onix->Steelix
- Rhyhorn->Rhydon->Rhyperior
- Poochyena->Mightyena
- Nosepass->Probopass
- Aron->Lairon->Aggron
- Anorith->Armaldo
- Snorunt->Glalie
- Shieldon->Bastiodon
- Burmy->Wormadam
- Glameow ->Purugly
- Pidove->Tranquill->Unfezant
- Drilbur->Excadrill
- Zorua->Zoroark
- Minccino->Cinccino
- Ferroseed->Ferrothorn
- Klink->Klang->Klinklang
- Wimpod->Golisopod
- Type: Null->Silvally
- Jangmo-o->Hakamo-o->Kommo-o
- Meltan->Melmetal
- Seel->Dewgong
- Togepi->Togetic->Togekiss
- Ralts->Kirlia->Gardevoir/Gallade
- Snover->Abomasnow
- Vanillite->Vanillish->Vanilluxe
- Foongus->Amoonguss
- Frillish->Jellicent
- Cubchoo->Beartic
- Larvesta->Volcarona
- Flabébé->Floette->Florges
- Pancham->Pangoro
- Swirlix->Slurpuff
- Galarian Ponyta->Galarian Rapidash
- Galarian Corsola->Cursola
- Galarian Darumaka->Galarian Darmanitan
- Wooloo->Dubwool
- Milcery->Alcremie
- Snom->Frosmoth
- Cleffa->Clefairy->Clefable
- Igglybuff->Jigglypuff->Wigglytuff
- Slowpoke->Slowbro/Slowking
- Lickitung->Lickilicky
- Happiny->Chansey->Blissey
- Mime Jr.->Mr. Mime
- Cherubi->Cherrim
- Munna->Musharna
- Spritzee->Aromatisse
- Fomantis->Lurantis
- Stufful->Bewear
- Hatenna->Hattrem->Hatterene
Edit (31.12.2019): Added Gen VIII additions.