A coat of many colours

The Blue Room by George Simenon
The Red Cat Cookbook by Jimmy Bradley
White Teeth by Zadie Smith
Black Mischief by Evelyn Waugh
Red Dragon by Thomas Harris

Black Orchids by Rex Stout
Sir Gawain and the Green Knight by Anonymous
Coyote Blue by Christopher Moore
The Devil in the White City by Erik Larson
The Golden Spiders by Rex Stout

OR

Blue: The History of a Color by Michel Pastoureau
The Colouring, Bronzing, and Patination of Metals by Richard Hughes
Colour Scheme by Ngaio Marsh
Matisse: From Color to Architecture by Rene Percheron
The Marriage of Heaven and Hell : in full color by William Blake

A Clockwork Orange by Anthony Burgess
Gathering Blue by Lois Lowry
The Rainbow by D.H. Lawrence
The Red and the Black by Stendhal
The Orange Girl by Jostein Gaarder

The Color Purple by Alice Walker
How Green Was My Valley by Richard Llewellyn
The Black Flower by Howard Bahr
Blue Diary by Alice Hoffman
Quick Brown Fox by Susan Kelly

Purple Hibiscus by Chimamanda Ngozi Adichie
Green Dolphin Street by Elizabeth Goudge
Black Beauty by Anna Sewell
The Virgin Blue by Tracy Chevalier
Oranges Are Not the Only Fruit by Jeanette Winterson

Red Light by Jefferson Parker
Into the Blue by Robert Goddard
Poor Man's Orange by Ruth Park
Rosa and the Veil of Gold by Kim Wilkins
Green Darkness by Anya Seton

I'm sure we've had a colour thread before!

Taking the thread title literally, what about
Joseph und seine Brüder by Thomas Mann?

Unfortunately, it's a only tetralogy, so it just misses the five-book bar. Do four thick books count as five...?

Color in my Garden: An American Gardener's palette
The Color of Water: 10th Anniversary Edition
The Mary Gilliatte Book of Color
Sexual Slang: A Compendium of Offbeat Words and Colorful Phrases
A Guide to Pink Elephants Vol. 2

I decided to go a red, white and blue theme this time around.

Red Rabbit by Tom Clancy
White Night by Jim Butcher
White Gold Weilder by Stephen R. Donaldson
Blue Adept by Piers Anthony
Task Force Blue by Richard Marcinko

From my LT list:

Red Square by Edward Topol
Red Mars by Kim Stanley Robinson
Green Mars by ditto
Doctor Who - Black Orchid by Terence Dudley
White Darkness by David A McIntee

The Red Tent by Anita Diamant
The Five Quarters of the Orange by Joanne Harris
The Yellow Wallpaper by Charlotte Perkins Gilman
Black Swan Green by David Mitchell
The Bluest Eye by Toni Morrison
Wild Indigo by Sandi Ault
The Trouble with Violet by Anne Mazer

and colors outside the rainbow (can you tell I've been looking at pantone wheels lately)...
The Salmon of Doubt by Douglas Adams
Rose in Bloom by Louisa May Alcott
Brooklyn Rose by Ann Rinaldi
Briar Rose by Jane Yolen
The Name of the Rose by Umberto Eco
Midnight Champagne by A. Manette Ansay
James and the Giant Peach by Roald Dahl
The Pistachio Prescription by Paula Danziger
White Oleander by Janet Fitch
Dragonfly in Amber by Diana Gabaldon
The Silver Chair by C.S. Lewis
Ruby Electric by Theresa Nelson
The Golden Compass by Philip Pullman
The Amber Spyglass by Philip Pullman
Scarlett by Alexandria Ripley
The Girl with the Silver Eyes by Willo Davis Roberts

I decided to go for all metallics to narrow it down a bit:

Sea of Silver Light by Tad Williams
The Golden Transcendence by John C. Wright
Burning Chrome by William Gibson
Guns, Germs and Steel by Jared Diamond
Iron Council by China Mieville

Edit: Forgot one I wanted to add: Quicksilver by Neal Stephenson

The Black Marble by Joseph Wambaugh
Black Beauty by Anna Sewell
The Black Stallion by Walter Farley
The Black Ice by Michael Connelly
The Black Echo by Michael Connelly

Since were going with themes ...

Black No More George S. Schuyler
The Bluest Eye Toni Morrison
White Fang Jack London
A Purple Place For Dying John D. MacDonald
Plum Bun Jessie Redmond Fauset

Half a Yellow Sun
Devil in a Blue Dress
Green Mansions
Green Darkness
The Golden Spiders
Red Sky at Morning
Where the Red Fern Grows
The Red Violin
Black Like Me
Crimson Joy
Blue Screen

Faded Coat of Blue by Owen Parry
The Man in the Black Coat Turns by Robert Bly
The Purple Coat by Amy Hest
White Coat: Becoming A Doctor At Harvard Medical School by Ellen L. Rothman
The Girl in the Red Coat by Roma Ligocka

Black Orchid by Neil Gaiman and Dave McKean
Brown Girl in the Ring by Nalo Hopkinson
The Ruby in the Smoke by Philip Pullman
The 13 1/2 Lives of Captain Bluebear by Walter Moers
Greywalker by Kat Richardson

A Red Death by Walter Mosley
The Red Badge of Courage by Stephen Crane
Blue Shoes and Happiness by Alexander McCall Smith
Blue Highways by William Least-Heat Moon
Devil in a Blue Dress by Walter Mosley
Murder Under Blue Skies by Willard Scott
Deep Blue Good-by by John D. MacDonald
Blue Deer Thaw by Jamie Harrison
The Blue Last by Martha Grimes
A Little Yellow Dog by Walter Mosley
Fried Green Tomatoes at the Whistle Stop Cafe by Fannie Flagg
These High Green Hills by Jan Karon
Leave the Grave Green by Deborah Crombie
The Golden Orange by Joseph Wambaugh
White Butterfly by Walter Mosley
Black Hearts and Slow Dancing by Earl W. Emerson

Behind the Blue and Gray by Delia Ray
The Black Pearl by Scott O'Dell
Charlie and the Chocolate Factory by Roald Dahl
Dress Gray by Lucian K. Truscott
The Green Mile by Stephen King
Rise of the Black Wolf by Derek Benz
The Twilight of the Golds by Jonathan Tolins
Under the Black Flag by David Cordingly

Black Alice
How Green was My Valley
A Study in Scarlet
White Lies
The Blue Sword

White Oleander
The Red Tent
Half of a Yellow Sun
The Color Purple
The Scarlet Pimpernel

Dragonfly in Amber by Diana Gabaldon
Black Girl White Girl by Joyce Carol Oates (got 2 there!)
The Green Mile by Stephen King
One Fish Two Fish Red Fish Blue Fish by Dr Seuss
Harold and the Purple Crayon by Crockett Johnson

White Cargo by Stuart Woods
The Picture of Dorian Gray by Oscar Wilde
Goldhawk Wrong touchstone by Patricia Werner
Blue Dahlia by Nora Roberts
Black Rose wrong touchstone by Nora Roberts

White Teeth by Zadie Smith
White Corridor by Christopher Fowler
Half of a Yellow Sun by Chimamanda Ngozi Adichie
Black and Blue by Ian Rankin
Red Dust by Gillian Slovo