Well if you can get a hold of anything truly red, or deep blue, and transparent, you can do a fairly good preliminary check.
Don't you have 3-D red and blue glasses handy, or transparent red or deep blue school project sheet covers?
Stack them up till the colour is so deep that the opposite color bars (for blue those are yellow green and red, for red those are cyan green and blue) become black or very dark when looking thru the colour. Of course proper colour filters are best.
Usually blue is adjusted first, with tint and colour, until the blue component colour bars (light grey on the left, cyan, magenta, blue) are equal in intensity or lightness while the other ones (yellow green red) look black with the blue filter.
Something like this:
Then you check if the red components (light grey, yellow, magenta, red) are equal intensity while the opposite ones (cyan, green blue) look black with the red filter.
If there's red push the red bar and maybe the yellow too will be lighter and more intense than the light grey bar on the left is through the red filter. Since skin tones are actually orangeish in chromaticy, they might be affected, and if you can't turn off red push, the only solution is to decrease saturation a little to get normal skin colours at the expense of the other colours. Your decision.
Summary:
thru blue:
grey yellow cyan green magenta red blue
thru red:
grey yellow cyan green magenta red blue
thru green:
grey yellow cyan green magenta red blue