Figured this might come in handy to some people looking for it.
Car Radio Battery Constant 12v+ Wire: Brown
Car Radio Accessory Switched 12v+ Wire: Light Blue
Car Radio Ground Wire: Black
Car Radio Illumination Wire: Light Green
Car Stereo Dimmer Wire: N/A
Car Stereo Antenna Trigger Wire: Black
Car Stereo Amp Trigger Wire: Light Blue
Car Stereo Amplifier Location: Under the Passenger Seat
Car Audio Front Speakers Size: N/A
Car Audio Front Speakers Location: N/A
Left Front Speaker Positive Wire (+): White/Yellow
Left Front Speaker Negative Wire (-): Blue/Green
Right Front Speaker Positive Wire (+): Red/Blue
Right Front Speaker Negative Wire (-): Red/White
Car Audio Rear Speakers Size: N/A
Car Audio Rear Speakers Location: N/A
Left Rear Speaker Positive Wire (+): White/Light Green
Left Rear Speaker Negative Wire (-): Pink/Brown
Right Rear Speaker Positive Wire (+): Light Blue/Brown
Right Rear Speaker Negative Wire (-): Light Green/Light Blue
The 2010 Mazda 3 radio wire color information above is updated as it is submitted by the Modified Life community.
Car Radio Battery Constant 12v+ Wire: Brown
Car Radio Accessory Switched 12v+ Wire: Light Blue
Car Radio Ground Wire: Black
Car Radio Illumination Wire: Light Green
Car Stereo Dimmer Wire: N/A
Car Stereo Antenna Trigger Wire: Black
Car Stereo Amp Trigger Wire: Light Blue
Car Stereo Amplifier Location: Under the Passenger Seat
Car Audio Front Speakers Size: N/A
Car Audio Front Speakers Location: N/A
Left Front Speaker Positive Wire (+): White/Yellow
Left Front Speaker Negative Wire (-): Blue/Green
Right Front Speaker Positive Wire (+): Red/Blue
Right Front Speaker Negative Wire (-): Red/White
Car Audio Rear Speakers Size: N/A
Car Audio Rear Speakers Location: N/A
Left Rear Speaker Positive Wire (+): White/Light Green
Left Rear Speaker Negative Wire (-): Pink/Brown
Right Rear Speaker Positive Wire (+): Light Blue/Brown
Right Rear Speaker Negative Wire (-): Light Green/Light Blue
The 2010 Mazda 3 radio wire color information above is updated as it is submitted by the Modified Life community.