I've heard this has been called fantasy's equivalent to Adams' Hitchhiker's Guide to the Galaxy trilogy. A fair comparison. Both authors are British, both series were started around the same time, 1979 and 1983 respectively, and both wrote witty, biting, funny, often hilarious satire. Colour of Magic is the first in Pratchett's 39 (so far) novel Discworld series. I read a recent article that Sir Terry, who is suffering from early onset Alzheimer's, is retiring and his daughter is taking over the series. Whereas H2G2's universe is the galaxy, the world in the Discworld series is a flat disc sitting on the backs of four elephants which stand on the back of the great turtle A'Tuin as it swims through space. Well. Why not? 
 Like H2G2, Colour follows around some zany, colorful characters, Rincewind, a hapless failed magician, and Twoflower, a clueless wealthy tourist, as they get into one adventure after another (actually just pawns in a great chess-like game of the gods) and run into other zany, colorful characters. They face frequent imminent death and also Death (the character), gods, trolls, dragons, fairies, and all kinds of fantastical beings. And who can forget Twoflower's fierce, protective Luggage. Common among all the adventures is magic. And, it had its own color "It was octarine, the colour of magic. It was alive and glowing and vibrant and it was the undisputed pigment of the imagination, because wherever it appeared it was a sign that mere matter was a servant of the powers of the magical mind. It was enchantment itself. But Rincewind always thought it looked a sort of greenish-purple." 
 All in all, Colour of Magic was great fun, an easy break from more serious stuff. I especially liked the stories of Liessa the great dragon rider of Wyrmberg and the hydrophobic wizards of Krull. I hope to visit Discworld again in the future.