Modern marks a key point of Magics design philosophy where they began to make the game more about creatures than about spells

Abstruse Archaic Adric, Mathematical Genius Ayesha Tanaka Azorius Guildmage Battlemage's Bracers Bind Bind (playtest) Biomancer's Familiar Brokers Confluence Brown Ouphe Burning-Tree Shaman Ceaseless Searblades Defabricate Deny the Witch Detention Vortex Disallow Dragon Whelp Drought Echo, Perceptive Prodigy Edifice of Authority Elvish Refueler Emerald Dragon Emerald Dragon Ertai Resurrected Farrelite Priest Gogo, Master of Mimicry Green Slime Heartstone Ice Cage Illusionist's Bracers Initiates of the Ebon Hand Interdict Kang the Conqueror Katabatic Winds Laboratory Drudge Linvala, Shield of Sea Gate Lithoform Engine Locus of Enlightenment Lost in Thought Louisoix's Sacrifice Lukka, Bound to Ruin Magewright's Stone Nalathni Dragon Nimble Obstructionist Oddric, Lunar Marquis (playtest) Orb of Origin (playtest) Ouphe Vandals Overcharged Amalgam Peter Parker's Camera Phenomena Recorder Power Artifact Primal Beyond Professor Hojo Quagnoth Ravager Wurm Repudiate // Replicate Repudiate // Replicate Reroute Return the Favor Rimewind Cryomancer Rings of Brighthearth Rust Scientist Supreme of A.I.M

Its whatever you need at that particular time
Long version: In the modern color pie, red is the color for fast-mana effects (called "rituals" after the old Dark Ritual)
One of the most obvious is some sort of Angel tribal deck, where rather than competing with Lyra Dawnbringer, Angel of Grace can benefit from the Angel lord