This may be common sense but what I do with the Ogri'la quest for simon says is just open up the talk bar (Enter) and as the colors go I just press the first letter of the color.
Example- The sequence is red, blue, green, yellow, green
I will have already opened the talk bar and once the sequence is done in it I will have "rbgyg" then you hit those colors and either say it or backspace it and get ready for the next one.
Hope this helps, happy questing !