About Colorado, from BoardGameGeek:
To explore Colorado, you will be armed with a marker and your map.
Each player has a personal map, and they start in one of two locations, opening that region for future exploration. Each player also has a hand of cards, and the cards in the deck come in six colors, with each color having cards numbered 1-3. On a turn, you ask another player to give you a card, e.g., a red 3. If they have one in hand, they must give it to you. If not, they must give you either a red card or a 3 - their choice. If they have no reds or 3s, you randomly draw one card from their hand.
If you already have the card you received in your play area, discard it and take a gold nugget; if not, place it in your play area. All players then take one of the two actions listed on this card:
Red and green cards either give you a nugget or let you pay 1-3 nuggets to play a card of value 1-3 from your hand; when you play a card from your hand, it can't already be in your play area, and you immediately take one of the two actions listed.
Gray and purple cards either let you draw three cards from the deck or discard two cards of the same suit to play a card from your hand into your play area.
Blue and orange cards either let you check off a space on your map in a region you've already opened or check off the next space on your railroad; if the space you checked has a reward, gain it immediately.
At the end of your turn, if you have all three cards of a color in your play area, discard them, then check the flag on a map region that is adjacent to a region that you have already opened. Finally, if you have fewer than three cards in hand, draw until you have three cards.
The purpose for all of this activity is to claim medals, which earn you points. You earn points for each region you open, and if you're the first player to open all regions of a color, you gain a medal worth bonus points. If you check all the spaces in a region, you earn a medal. If your railroad reaches the end of the line, you earn a medal. If you check all spaces with a certain symbol on your map, you earn a medal. Once a player has collected, the game ends at the end of that turn, then you tally all points to see who wins.
Use shrewdness and discernment when calling or giving cards that you can take advantage of without helping your opponents too much. Ideally, you will be able to earn the points of the many medals scattered on your individual sheet route, as well as on the common bounty board.
