Gardena Blue & Green Fertiliser Discs

I am clearing out my garage - first time since we moved here in 1986 !!
In one drawer I found a pack of Gardena fertiliser 'discs' that I had bought along with a dispenser for the impulse spray unit.
Basically, the dispenser was a clear cylindrical unit that fitted between the spray unit body & trigger and the spray head. As water flowed through the dispenser it diluted the disc and so you fed the plants as you watered.
My problem is that the spray unit and dispenser are long gone, leaving me with a full pack of blue discs and a jar with green disc powder.
Of course, I have no idea what fertiliser is which colour - instinct tells me that the green is nitrogen and the blue potash but that doesn't match as I think that I would likely have used all the potash ! ?
Any members got any better memories than myself ?? (I searched the internet but no signs of anything under either Markt (UK) or Gardena) .
Thanks

 

Hi @IanMacK
I found this page
https://www.amazon.co.uk/Gardena-6446-9Pack-Fertilizer-Disks/dp/B002VED3JS
it was for lawns. So that implies green is nitrogen

 

Nitrogen in it's raw state is white-ish in colour so to for urea,

if you have granule fert you will see all colours of the N P K but if you have prill fert all N P K is made into one prill so you get a mix of colours to make one

 

Thanks CarolineL
My intuition was that green=nitrogen and blue=potash but I couldn't rationalise that I would have used so much green for grass.
Anyway, that's good news - means that I have a stock of potash feed - I'll just have to experiment with the dosage - I'll grind up the discs and mix in my watering cans.

 

Hi @Jiffy - I meant that they dyed the tablets to indicate different contents - not the actual colour of the original fertiliser.