have old 2 way, 2 gang light switches, old colours but can't connect them to the new switches as the connections are different. On the new ones the connections are comm,L1,L2.On one terminal has 2 red wires, 1 black wire and the earth wire connected to metal back plate. On the other terminal there is 1 red wire, 1 black wire .
2 Gang means two separate switches mounted on the same plate - for switching two separate lights.
2 Way means controlling one light from two separate sattions such as a landing light that may be switched from upstairs or downstairs.
Terminal means the hole with a screw into which you put the wire(s)
Old light switches often have just two teminals and from what you say one of the terminals in one of the switches had two red wires going into it - Put these in the Com or common terminal hole. Put the associated black wire into either L1 or L2 it doesn't matter which but remember it will be live when the switch is on.
For the other switch place the Red wire in Com and the Black wire in L1 or L2 as you wish.
You may wish to consult these two links...
Operating one lamp from two places (two way switch)
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix lighting.