In case you missed it:
>"Tank" keystones (green)
Grasp combined with Fleet Footwork: also gain movement speed from proc'ing on champions, can heal and gain movement speed on minions too, but is much weaker.
Aftershock
Hourai Elixir: gain health regen and slow resist. At low health, gain a burst of health regen and slow immunity for a few seconds
>"Fighter" keystones (yellow)
PTA combined with First Strike: After 3 attacks, enemy becomes vulnerable. Gain a portion of gold based on the total damage you dealt.
Lethal Tempo
Conqueror
>"Burst" keystones (red)
Electrocute: Also reveals now
Dark Harvest
HoB: grants some passive attack speed
>"Mage" keystones (purple)
Arcane Comet
Phase Rush
Soul Fire: Deal DoT damage, heal based on that damage and gain very small bonus movement speed during proc. Takedowns heal you and grant extra movement speed for a few seconds
>"Support" Keystones (blue)
Aery combined with Guardian: Passively also gain a shield, taking burst damage shields everyone around you too.
Glacial Augment
Athena's Wrath: Deal additional bonus damage. Damage heals you and your nearby allies, enemy takedowns heal your entire team.
(This is for the Lux, Brand, Zyra, Xerath supports...)
>"Specialist" Keystones (white)
Klepto with a dash of ancient coin and ornn passive: Gain very small gold from hitting enemies. Enemies periodically drop ancient coins, collect them for a bigger wad along with small health and mana restore. Can also buy items without recalling (long cooldown on this one)
Spellbook: Passively gain summoner spell cool down. Occasionally unlock Super Summoner Spells, up to 5 per game. (assuming it goes up to 40+ min)
Entropy Edge: Gain bonus AD per AP; Gain bonus AP per AD. Gain attack speed and bonus damage during champion combat.
Also, when you open the rune page, it looks like a pentagram with red (right), blue (bottom left), yellow (top), green (bottom right), purple (left) and white (center)