You are allowed to use colours outside of your scheme. Changing the colours on something so common as Google Maps can get confusing.
Regarding navigation, I'd say your Prospective drop-down fits the typical understanding of drop-down navigation. The others perhaps not as much.
Being consistently inconsistent doesn't count - I'm talking about the inconsistencies in drop-down style, size, link style, presence of link rollover feedback. Bringing these more in line with each other would be a lot better for general usability and user experience.