See sketch Strip_Test.ino for testing performed.  I found that the brightness control on this strip is non-linear.  Brightness is a unit8, but at value over 70 a fully blue LED will start to decrease in brightness and at above 100 goes completely dark.

For five levels of brightness the following seems to be a reasonable choice.

uint8_t auBrightness[] = {1,3,5,8,25};

And for colors I phoned a friend and got the following values for the ROYGBIV colors

//colors
#define RED 255, 0, 0
#define ORANGE 255, 80, 0
#define YELLOW 255, 255, 0
#define GREEN 0, 255, 0
#define BLUE 0, 0, 255
#define INDIGO 75, 0, 130
#define VIOLET 148, 0, 211
#define WHITE 255,255,255
#define TRUE_WHITE 0, 0, 0, 255
#define OFF   0, 0, 0, 0

Here is the display at a brightness of 8 with the LEDs set to my initial AoA scheme [Red, Red, Orange, Blue, Yellow, Yellow, Green, Green]