SPD
[Metamerism](https://texonom.com/metamerism-722f85db8d03403e91b70d0edc0ec3a7) 


## Spectral Power Distribution
They stimulate three cones so sampled as three numbers
So different SPD can result same color
$$I(\lambda)$$
입력 스펙트럼 [Radiometric](https://texonom.com/radiometric-1c00577232d44fc1b037456bd9b8e5b8) 그자체










