You may have noticed, but each color (type) of Pokemon card has cliche
traits.  By recognizing these traits, you can aid your own Pokemon or defend
youself against your main weakness.  Here are the most dominant traits for
each type(elaboration to come directly)
Water-lots of damage for lots of energy
Grass-status effects
Fire-major energy discarding
Psychic-Pokemon Powers
Electric-self-damaging attacks
Fighting-attacks that damage
Dragon-coin flips

Water-lots of evolved Water types have attacks with high damage and high
energy costs.  That's what made Raindance so wildly popular.  Water decks
should have plenty of energy.  A deck with weakness to water should take
advantage of the fact that Water types like Gyarados, Blastoise, and Articuno
take time to power up(provided Blastoise doesn't Rain Dance)
Grass-grass is famous for status effects.  That and Scyther, but we'll come
back to him.  A deck with weakness to grass should keep Full Heal and Full
Heal Energy on hand, hindering their opponents' offense(most status effect
attacks do little, if any, damage)If you're playing grass decide which status
effect you'd most like to inflict, since 3 out of the 4 negate one another.
Fire-this is the most well known color-specific trait.  Fire pokemon discard
a lot of energy.  Fire decks need the most energy of all the types, a way to
get it out of the discard pile(or prevent it from getting there at all) and
some defense against water-types.Anti-fire should have some removal tactics.
Psychic-Good Pokemon Powers are found in all types, but unless the deck is
built around the Power, none is as dependent on the power as Psychic types. 
A Blastoise still has Hydro Pump, a Dark Muk still has Sludge Punch, an
Erika's Dratini still has Tail Strike, but a Fossil Haunter or Mr. Mime in
the prescence of Goop Gas is dead in the water.  Also unique to Psychics are
their weakness to their own type.  A psychic deck should have some colorless
types that are psy-resistant.
An anti-psy deck might want to look into Goop Gas.
Electric-The best thing I can find for an Electric deck is Defender.  Block
the damage you do to yourself, and 20 of theirs.  Vermillion City Gym could
help too, as well as fighting resistant colorless pokemon.  Surge's Fearow
suggests itself.
Fighting-You probably want to know what I mean by "attacks that damage".  I
mean that fighting attacks rarely do anything other than damage.  Fighting
Pokemon rarely have status effects or such.  A fighting deck should have
PlusPower, an anti-fight deck(usually an Electric deck) should have Defender.
 This works out nicely.
Dragon-I'm talking about the Dragonite line, not Gyarados.  All of these
pokemon except Base Dratini and possibly Erika's Dragonair which I have yet
to see require at least one coin flip.  I don't know of any way to counter or
aid this yet, but I'm working on it.  You think about it too, all right? 
Especially if their in your deck.
In summation, I hope this information aids you and thank you for your time.
Dragon Rage
bmoor87785@aol.com