Red's strengths are sacrificing resources for great power dealing 'direct damage' to players or creatures and destroying artifacts and lands. Black's strengths are destroying creatures forcing opponents to discard cards making players lose life and returning creatures from graveyards. Blue's strengths are drawing cards taking control of opponents cards 'countering,' or negating opponent's spells and 'flying' creatures or creatures that cannot be blocked.
Blue is the color of deceit and intellect.White's strengths are a host of small creatures that collectively become powerful life-gaining reducing the powers of opposing creatures and 'equalizing' cards that wipe large swaths of cards off the board.
Incorporate different colors into your deck: White, Blue, Black, Red, and Green.