HDMI isn't on 3 separate connectors.
Search for HDMI connector and you'll see what I mean.
The DVD connectors are probably yellow for composite video, red for the right audio channel, and white or black for the left channel of stereo audio.
Its likely the red and white connectors on your TV are the sound channels and possibly the green connector is for video.
You are unlikely to create any problems by trying.
It may be helpful to find the manuals. May be available online, if you can determine the model number(s)
dsd
September 2017