Exercise 25 Colour into tones in black and white

I have made a still life arrangement that includes the colours red, yellow, green and blue. I found a blue bowl, cut a pineapple in half to show the yellow and used its spiky leaves for the green and placed some strawberries for the red.
I put all of these onto a board and then into a upturned box lid that was grey to show my grey card. Although the backdrop is also grey and shows this. I photographed this in colour and then went into lightroom to change to black/white and also used the preset filters for red, yellow green and blue.
Here are the results

 Coloured

Black + White

Red Filter

Yellow Filter

Blue Filter

Green Filter

Not sure if I should have used more solid shapes as the red and yellow pictures both showed up really light due to the large yellow area of the pineapple, the blue showed lots of detail in the yellow pineapple.
It was interesting to see how the filters affect the colours