Colour into tones in black and white

This was an interesting exercise. Unfortunately I could not find the colour sliders in photoshop under image/adjustments. Perhaps I have an older version of photoshop. Instead I used "enhance" to convert the photograph I took to black and white. I then adjusted the black and white photo to have more blue, more red and more green. Unfortunately there was no adjustment for yellow. There are very subtle differences in the photographs but in retrospect I might have been better to adjust the intensity setting when making these changes. None the less I can see from the course work that a black and white image can be adjusted by understanding colour.