Like this:
the "open project" item's color is grey.
Like this:
the "open project" item's color is grey.
You need to first create a project using File -> New Project. Then the project you've created must be closed before you can then open it.
Perhaps you want to Import a Project to Eclipse From an Archive File.
Project > Open Project and Project > Close Project may no be what you think, they apply to projects that are already in the workspace and are closed/open respectively. From the Eclipse documentation:
When a project is closed, it can no longer be changed in the Workbench and its resources no longer appear in the Workbench, but they do still reside on the local file system. Closed projects require less memory. Also, since they are not examined during builds, closing a project can improve build time.
You are probably looking for File > New > Project that would open the following wizard (select the type of project you want to create and follow the steps):
To import an existing Eclipse project, use File > Import > Existing Project into Workspace.