Find the odd one out. Red colour, Yellow colour, Violet colour, White colour

Yellow coloured compound is:

Yellow colour of the flame indicates

Describe the sample space for the indicated experiment: One die of red colour,one of white colour and one of blue colour are placed in a bag.One die is selected at random and rolled,its colour and the number on its uppermost face is noted.Describe the sample space.

Yellow colour in the flame denotes:

Yellow colour of faeces is due to

What is the ratio of velocity of red colour light to velocity of violet colour of light in vacuum ?

Yellow colour of faeces is due to :