Mnemonics
Seeing as the colours can be matched up to the spectrum
Love can stop bad people
1) Lithium, 2) calcium, 3) sodium, 4) barium, 5) potassium
1) Red 2) Red/orange 3) yellow 4) green 5) skips to purple - but potassium is purple is easy to remember anyway
I don't know of that works for you but it is how I do it!