This is the 5034th most frequent Spanish word.
espectro
Spectrum; ghost; range.
In this sentence, 'espectro' is used to describe a range or band of colors.
El espectro de colores en el arcoíris abarca desde el rojo hasta el violeta.
The spectrum of colors in the rainbow spans from red to violet.
Here, 'espectro' refers to a spectral appearance, often interpreted as a ghost.
Se dice que un espectro ronda la antigua mansión en las noches.
It is said that a ghost haunts the old mansion at night.
In this usage, 'espectro' signifies a range or extent over which something applies.