Function is_yellow

tests/SphericalEffect.cpp:56–56

// Loose classifiers for our colored guide lines
static bool is_red(QColor c)    { return c.red()   >= 200 && c.green() <= 60 && c.blue() <= 60; }
static bool is_yellow(QColor c) { return c.red()   >= 200 && c.green() >= 170 && c.blue() <= 60; }

/* ----------------------------------------------------------------------------
 * Invert behavior vs Yaw+180 (Equirect input)