You've just about got the idea although it's not really about carbs/protein. There are two basic plans - red and green.
On the red you can eat unlimited amounts of lean meat and fish, eggs, quorn, fruit and most vegetables and fat free yoghurt.
On green you can eat unlimited amounts of pasta, rice, noodles, grains, potatoes, pulses, quorn, eggs, fruit and all vegetables and most fat free yoghurt.
No weighing or measuring needed for these.
On top of that you have your healthy extras to make sure you get your daily dose of calcium (A choices - milk and cheese) and fibre (B choices - wholemeal bread, wholegrain cereal, dried/stewed/canned fruit, cereal bars, nuts, meat/fish (on green plan), cheese (on green plan), wholemeal pasta (on red) and pulses (on red). You choose two items from the A list and two from the B list. These have to be weighed.
Then you also have your syns - 5 to 15 a day - for treats or to add variety to your recipes. Every food has a syn value and it is up to you to choose how you 'spend' your syns.
On the new Extra Easy plan you can eat unlimited amounts of any of the foods listed above for the red and green plans, but you can only choose one Healthy Extra A and one B. You still get your syn allowance.
You can choose to do the same plan every day or you can switch between them, even doing a different plan every day if you wish. Many people do extra easy every day while vegetarians do green every day. It depends what you enjoy eating really. If you like your meat then red will suit you, if you like your pasta and rice then go green, if you like both equally then try extra easy.