LCD handheld TV not displaying colour

[SAVVYCLUTTER]

I bought a 1985 Citizen TC53 earlier this
year and used it with a VCR several times.
Yesterday, it was displaying in black and
white and the batteries had leaked. I
replaced them, cleaned the compartment
and tried adjusting brightness and colour.
Nothing looks broken inside. I have a
multimeter but don't know what to test.