Blinks API Reference
Blinks API Reference (lite) - glanceable reference
API Source Code - absolute truth (would I lie about something like that? 🙂 )

Display

void setColor(color);
// sets all 6 pixels on all faces to the same color

void setFaceColor(face, color);
// sets a single pixel on a face to this color

Colors

Color makeColorRGB(red, green, blue);
// R, G, and B values [0-255]

Color makeColorHSB(hue, saturation, brightness);
// H, S, and V values [0-255]

Color dim(color, value);
// returns the color passed in a dimmer state (31 levels of brightness)

#define RED     makeColorRGB(255,   0,   0)
#define ORANGE  makeColorRGB(255, 127,   0)
#define YELLOW  makeColorRGB(255, 255,   0)
#define GREEN   makeColorRGB(  0, 255,   0)
#define CYAN    makeColorRGB(  0, 255, 255)
#define BLUE    makeColorRGB(  0,    , 255)
#define MAGENTA makeColorRGB(255,   0, 255)
#define WHITE   makeColorRGB(255, 255, 255)
#define OFF     makeColorRGB(  0,   0,   0)

Button

/*
 *  All button handling is done with flags, so when you call a function, 
 *  it returns the value of the flag (i.e. whether or not that action 
 *  has occured) and only when you have called the function will it reset 
 *  the flag to false
 */

bool buttonPressed();
// a flag is set to true on the change from button up to button down
// buttonPressed() returns that flag and sets it back to false

bool buttonReleased();
// a flag is set to true on the change from button down to button up
// buttonReleased() returns that flag and sets it back to false

bool buttonSingleClicked();
// a flag is set to true when the the button goes from down to up
// only once in under 330ms. The flag is set exactly 330ms after the button is up
// buttonSingleClicked() returns that flag and sets it back to false