Bridge computations

The tables show what you can score on a contract that makes. Some of the fields are coloured like this, like this, or like this. They represent doubled or redoubled contracts. That a field has been coloured in this way, means that the underbid contract scores better than the corresponding contract bid to the limit.

Example:
1 minor, not vulnerable, doubled, made with an overtrick scores 240 points. If instead you bid 2 minor and it makes, you get 90 points. So it's better to play it as 1 minor doubled.
If you bid 2 minor and get it doubled and it makes, you get 180 points. It's still better to play it as 1 minor doubled.
However if 2 minor is redoubled, you get 560 points which is better than the other results.

Therefore the field corresponding to 1 minor, not vulnerable, doubled, 1 overtrick, has this colour.

This colour means that there is no (re)doubled contract on a lower level that scores as much (same suit and number of tricks). It must be bid to the limit.

Uncoloured fields mean that there is another contract with the same number of tricks that scores better.

This colour coding may seem superfluous - you can't order the opponents to double. Nevertheless I think that it gives you an idea of some conditions about doubled/redoubled contracts, and anyway one can just ignore the colouring.