So there are the 4 basic elements that almost everyone agrees on, with possible plus and minus status effects and associated colors:

Air = Yellow/White
+Hasten movespeed
-Slow movespeed
Water = Blue
+
-Energy loss (drowning)
Earth = Green
+
-
Fire = Red/Orange
+Increased damage
-Burn damage over time

A game would typically have an attack or spell do damage with an occasional added effect based on the element used, be it a debuff to the enemy, or a self buff to the user. So my first question is what can I add as a buff/defubb associated with water and earth?

Secondly, 4 seems to not be enough anymore, so I've been trying to think up a few more elements (including, but not limited to, Logia fruits from One Piece and Elemental Types from Pokemon):

Chaos = Purple/Black
+Teleport something
-Teleport something

Ice = Light Blue
+Magic defence up?
-Freeze

Steel = Silver/Gray
+Defence up
-Defense down

Sand = Light brown
+?
-Root

Electric = Bright Yellow
+?
-Paralysis

So my second question is what are some creative buffs/debuffs you might associate with various elements? My definition of an element is rather loose, just make sure there's also some color associated with whatever element you use. You are free to ignore the laws of physics for creativity's sake. I'm just looking for possible ideas to use.

P.S. I was going to use the alchemy game to get a list of elements, but after I got bullet, gunpowder, and A-Bomb, I decided to stop.

Not sure what game you're going for, but here goes:

Electricity = Bright White
+Magic Reduction and reduced damage is converted to energy, bonus magical power for a short period of time, or something similar
-Paralysis (as you suggested)
Earth = Brown (in place of sand)
+Increased Armor/Defense
-Mud (decreases attack speed and/or movement speed)

Psychic = Dark Purple
+Increased Spell Power, Increased Magic Resistance (reduction) or Decreased Cast Time
-Good ol' "Stun", Decreased Magic Resistance, Decreased Spell Power, or Increased Cast Time

Ice = Light Blue
+Increased Magic Resistance (seems like Earth would be best against physical, but Ice would maybe reflect some kind of magic...?)
-Slows physical attackers when they attack you or freezes someone to the ground (good ol' stun/immobilize?)

Light = Yellow
+Increased Health, Health Regeneration or Heal
-Blind (decreases chance to hit, maybe even give it a flash-grenade effect where it whitens your screen temporarily)

Nature = Green
+Increased Health Regeneration
-Roots (Immobilize or Stun, possibly with a DoT involved)


Just some things I could think of on the spot.
Good luck!

Yes, that is pretty much what I am looking for. Those 5 are pretty good, but my goal is something on the order of 99 elements, each having a plus, minus, and color (gradients and mixtures included) if that's realistic at all. (is it?)

There will likely be many instances of a "repeat", for example, volcano, lava, and magma are essentially the same element with minute differences.

Also, I've just learned of a game called Suikoden, which is known for it's use of 108 distinct characters with unique(?) abilities. Has anyone else heard of this, and if so, could it be useful to look into for creating a set of 99 elements?

I've played a couple of the Suikoden games. They're OK for character diversity, but a lot of them play pretty similarly. The series certainly won't give you 99 ability categories; they're nowhere near that unique.

I don't think that you should get so boxed in by the 4 classical elements (5 really, but that's not enough to get you were you want to go). It's not that everyone agrees on them, it's just that they were the dominant theory for a while in Western civilizations, conceptualized by a famous and respected thinker. In trying to describe the world around themselves, people took a shot. There's no reason that you have to be locked into one conceptualization as a result.

There's nothing wrong with them of course, but you aren't going to get to 99 unique or even distinct elements. A repeated one is an unnecessary one, and there is only so fine an adjustment you can make between similar elements. If you had a controller with 99 buttons, and they all made you jump, duck, or run (to differing degrees, maybe), what would you think of it? Would you say "Wow, 99 different things I can do! I can't wait to explore this variety!", or "It seems a bit unreasonable that this game will make me learn the functions of 99 buttons for so little practical reward."

If you really want 99 options (which seems like it would be hard to distinguish between by eye-- you're not comparing paint swatches), maybe you should start with a wheel of colors and set as many types of effects as you'd like to see at different points around the wheel, keeping ones that you feel oppose each other at opposite sides. Then you can fill in different combinations of effects as you move between any two points. Or do whatever number of elements you can think of, and then list as many combinations as you need/want between them. But starting at water, fire, earth, etc., you are going to have a hard time getting to 99 meaningful options.