it turns black
Sodium hydroxide turns red litmus paper blue.
I think it is supposed to be PURPLE. Because of the following:It turns red when placed in acidic solutionIt turns blue when placed in alkaline solutionAnd purple when placed in neutral.
You get the color you get if you subtract green from red
Red and green
Red/blue red turns to blue to detect alkali blue turns to red to detect acid
You are a primary colour.
Green red and pink
Green is the color that universal indicator turns to when it is neutral.
green
The colours are actually very different. Red is a primary colour and green is secondary colour. If you look at a colour wheel red is opposite green meaning they are complimentary colours so they work well together.
the opposite colour to red on the colour wheel is in fact and truely green.
Each secondary colour is situated opposite the one colour not used in its creation. Therefore the opposite colour to green on the colour wheel is red.