The main themes of The Colour of Magic stem from the differing perspectives of Rincewind, a failed wizard, reluctant guide, and very reluctant hero, and Twoflower, the indefatigable tourist. Rincewind's only goal is to muddle through somehow, and the hilarious send-ups of fantasy adventures reveal the difficulties inherent in achieving even such a modest aim. Death, complete with scythe, grinning skull, and sepulchral voice, shows up again and again, impatient to harvest Rincewind's soul. Fate, personified, has a special grudge against the failed wizard. Fate and Lady Luck play dice for his soul, and even when Lady Luck wins, his life is only prolonged, not made more comfortable or less frightening. Perhaps the quintessential moment comes when Rincewind finds himself hanging from the branch of a tree, having escaped a bear, with irate and hungry wolves surging about below him, Death lolling with scythe at the ready on the next branch, a poisonous snake slithering towards him, the branch starting to break, and "the largest hornets' nest he had ever seen, hanging right in his path." It is ridiculous, of course, but life is ridiculous for Rincewind. No victory against all odds, no preposterous escape, can save Rincewind from the struggle of living, and yet he keeps bungling on stubbornly rather than die.
Twoflower is the Don Quixote to Rincewind's Sancho Panza, although Pratchett has reversed the physical attributes of the characters, making Rincewind scrawny and Twoflower tubby. Twoflower has left his home to see marvelous things; his invariable reaction to the long succession of brawls, muggings, spells, dragons, shipwrecks, and menacing temples he and Rincewind encounter is to cry out in delight and reach for his camera (a box containing an ill-tempered but fast painting imp). He pulls the reluctant Rincewind along with him by the power of his incurable optimism and unquenchable sense of wonder. A diminutive and cherubic Don Quixote, he simply refuses to see the world except through his imagination, and his imagination proves strong enough to incarnate a dragon. Like Cervantes' knight, his vision helps him to rise above or breeze past mere reality; like the innocent heroes of fairy tales (although unlike Don Quixote, he always emerges unscathed). Ultimately, then, he is more "right" than the realists around him; improbable though it often seems, he imposes his transforming vision on the world.