Another way to add color to the entry is with plants in containers. Container planting allows you to change the color easily from season to season, perhaps starting with an array of bulbs in spring, followed by annuals the rest of the year. Container plants are especially helpful if the entry is shady. You can also plant duplicate containers of sun-loving annuals, keeping one in a sunny part of the garden and the other by the door, and rotating them weekly.
An overhead canopy is helpful in the transition from garden to home, especially if the structure is about the same height as the ceiling of the room you enter. A canopy also keeps you and your guests dry upon entering your home.
If you have an overhead structure, either at the entry itself or along the pathway to the entry, consider covering it with a vine or other climbing plant. A bower of green can soften a stark structure.
Because the entry garden is visible to all who come to your home, and because guests have time to take in this garden, maintenance is an important concern in planning and design. Be realistic about how much maintenance you're willing to do and design accordingly. Even if you aren't installing an irrigation system or lighting anywhere else in the garden, consider it for the entry garden. This will help the area look attractive year-round.
Hardscape needs maintenance, too. Cracked concrete and loose or missing bricks make a poor (and potentially unsafe) first impression. Add a weekly inspection of the entry as part of your gardening routine.