Maybe a repetition for you, but I want to go save:
A green coloured stat = +10%
A orange coloured stat = -10%
The blue numbers (ev´s) = 0,25 stats (so 4 ev´s are 1 stat at level 100)
Orange numbers (iv´s) = 1 Iv = 1 stat at level 100
White numbers = Your stat in total
The reason why you are confused is because your Poke might not be at level 100, every iv or ev is
manipulating your total stat (The white numbers) but the effect is not very high at low level Pokes.
Since my english is not the best maybe once again in other words: You get higher *white* stats with higher iv´s and higher ev´s and the nature of the Pokemon (green, orange coloured stats).
This numbers has no other use then increasing your final stat (white numbers).
Edit: If you are still confused: https://pokemonrevolution.net/forum/viewtopic.php?f=123&t=66600