Because oven cleaner contains Sodium Hydroxide (Na OH), a 'strong' alkali/base, to dissolve the grease, it would change Universal Indicator a deep blue/purple colour.
Red and if you want to make your own indicator you could use red cabbage (truly works)
Using the pH-paper Merck art. 9565 the color is brick-red.
red
purple
Dark Purple
red
colourless
rainbow
YYEESSS
It will turn green! :)
it turns red
green
rainbow
YYEESSS
black
Bronze
It will turn green! :)
blue
it turns red
green
When universal indicator is put in water soluion of alkalis (base) it indicates significant blue colour.
red
Purple:)
I belive its red or my nose