If you are talking about the wiring of buildings/houses then blue would be a hot with ac current. If you mean wire in electronics then it would also "usually" be a positive but if there is any danger you should never assume. A tester could save you from having to buy a new component or your life.
AnswerThe European convention is that blue insulation indicates a neutral conductor, brown, black, or grey insulation indicates a line conductor, and a yellow/green striped conductor indicates an earth conductor.
Positive wire is red, at least on automobile batteries.
Hot is positive.
Yes, the red wire is a positive wire (+) and the black wire is a negative wire (-) :D
yes.. had to find out myself with a multimeter and phone test,, white wire is positive on a samsung travel adapter.
Commonly the red should be positive but not always. Use a volt meter to find out for sure. Really need more information as to what this wire is for and where it is located to give a good answer.
The left rear speaker wire positive is -Yellow/Blue negative is - Black/Blue The right rear speaker wire positive is - Yellow/Red negative is - Gray/Red
1987 Mazda B2000 Car Radio Wire SchematicCar Radio Battery Constant 12v+ Wire: Blue/RedCar Radio Accessory Switched 12v+ Wire: Red/BLackCar Radio Ground Wire: ChassisCar Radio Illumination Wire: Blue/WhiteCar Stereo Dimmer Wire: N/ACar Stereo Antenna Trigger Wire: N/ACar Stereo Amp Trigger Wire: N/ACar Stereo Amplifier Location: N/ACar Audio Front Speakers Size: 4″ SpeakersCar Audio Front Speakers Location: DashLeft Front Speaker Positive Wire (+): Blue/RedLeft Front Speaker Negative Wire (-): Blue/YellowRight Front Speaker Positive Wire (+): BlueRight Front Speaker Negative Wire (-): Blue/WhiteCar Audio Rear Speakers Size: 4″ SpeakersCar Audio Rear Speakers Location: Side PanelsLeft Rear Speaker Positive Wire (+): Blue/RedLeft Rear Speaker Negative Wire (-): Blue/GreenRight Rear Speaker Positive Wire (+): Blue/WhiteRight Rear Speaker Negative Wire (-): Blue/Green
Red or Blue
CAR AUDIO FRONT SPAEKERS LOCATION: DOORS LEFT FRONT SPEAKER POSITIVE (+) WIRE: TAN LEFT FRONT SPEAKER NEGATIVE(-) WIRE: GRAY RIGHT FRONT SPEAKER POSITIVE (+) WIRE: LIGHT GREEN RIGHT FRONT SPEAKER NEGATIVE (-) WIRE: DARK GREEN CAR AUDIO REAR SPEAKERS LOCATION:REAR DECK LEFT REAR SPEAKER POSITIVE (+) WIRE: BROWN LEFT REAR SPEAKER NEGATIVE (-) WIRE: YELLOW RIGHT REAR SPEAKER POSITIVE (+) WIRE: DARK BLUE RIGHT REAR SPEAKER NEGATIVE (-) WIRE: LIGHT BLUE
The modern colours are Brown = positive : Blue = negative : Yellow and green = earth.
Car Radio Battery Constant 12v+ Wire: Orange Car Radio Accessory Switched 12v+ Wire: Yellow Car Radio Ground Wire: Black Car Radio Illumination Wire: Brown Car Stereo Dimmer Wire: Gray Left Front Speaker Positive Wire (+): Tan Left Front Speaker Negative Wire (-): Gray Right Front Speaker Positive Wire (+): Light Green Right Front Speaker Negative Wire (-): Dark Green Left Rear Speaker Positive Wire (+): Brown Left Rear Speaker Negative Wire (-): Yellow Right Rear Speaker Positive Wire (+): Dark Blue Right Rear Speaker Negative Wire (-): Light Blue Car Radio Battery Constant 12v+ Wire: Orange Car Radio Accessory Switched 12v+ Wire: Yellow Car Radio Ground Wire: Black Car Radio Illumination Wire: Brown Car Stereo Dimmer Wire: Gray Left Front Speaker Positive Wire (+): Tan Left Front Speaker Negative Wire (-): Gray Right Front Speaker Positive Wire (+): Light Green Right Front Speaker Negative Wire (-): Dark Green Left Rear Speaker Positive Wire (+): Brown Left Rear Speaker Negative Wire (-): Yellow Right Rear Speaker Positive Wire (+): Dark Blue Right Rear Speaker Negative Wire (-): Light Blue
Car Radio Battery Constant 12v+ Wire: Blue/Red Car Radio Accessory Switched 12v+ Wire: Blue/Yellow Car Radio Ground Wire: Black/White Car Radio Illumination Wire: Red/Black Car Audio Front Speakers Size: 5 1/4″ Car Audio Front Speakers Location: Doors Left Front Speaker Positive Wire (+): Brown/Black Left Front Speaker Negative Wire (-): Green/Red Right Front Speaker Positive Wire (+): Green/Orange Right Front Speaker Negative Wire (-): Blue/Orange Car Audio Rear Speakers Size: 5 1/4″ Car Audio Rear Speakers Location: Side Shelves Left Rear Speaker Positive Wire (+): Blue Left Rear Speaker Negative Wire (-): Yellow Right Rear Speaker Positive Wire (+): Pink/Blue Right Rear Speaker Negative Wire (-): Brown/Red
Car Radio Battery Constant 12v+ Wire: Orange Car Radio Accessory Switched 12v+ Wire: Yellow Car Radio Ground Wire: Black Car Radio Illumination Wire: Gray Car Stereo Dimmer Wire: Brown Left Front Speaker Positive Wire (+): Tan Left Front Speaker Negative Wire (-): Gray Right Front Speaker Positive Wire (+): Light Green Right Front Speaker Negative Wire (-): Dark Green Left Rear Speaker Positive Wire (+): Brown Left Rear Speaker Negative Wire (-): Yellow Right Rear Speaker Positive Wire (+): Dark Blue Right Rear Speaker Negative Wire (-): Light Blue
2005 Chevrolet Malibu Stereo Wiring Information Radio Battery Constant 12v+ Wire: Red/White Radio Ground Wire: Black/White or Black Stereo Antenna Trigger Wire: Pink Left Front Speaker Positive Wire (+): Tan Left Front Speaker Negative Wire (-): Gray Right Front Speaker Positive Wire (+): Light Green Right Front Speaker Negative Wire (-): Dark Green Left Rear Speaker Positive Wire (+): Brown Left Rear Speaker Negative Wire (-): Yellow Right Rear Speaker Positive Wire (+): Dark Blue Right Rear Speaker Negative Wire (-): Light Blue
I found the pinout at http://www.installdr.com to be extremely helpful.The wire coloring (wiring diagram) for my 1997 Mazda Protege LX was as follows:Car Radio Battery Constant 12v+ Wire: Blue/RedCar Radio Accessory Switched 12v+ Wire: Pink/BlackCar Radio Ground Wire: Black/YellowLeft Front Speaker Positive Wire (+): Blue/OrangeLeft Front Speaker Negative Wire (-): Violet/WhiteRight Front Speaker Positive Wire (+): White/RedRight Front Speaker Negative Wire (-): Yellow/RedLeft Rear Speaker Positive Wire (+): OrangeLeft Rear Speaker Negative Wire (-): YellowRight Rear Speaker Positive Wire (+): Green/BlackRight Rear Speaker Negative Wire (-): Green/Orange
I found the pinout at http://www.installdr.com to be extremely helpful.The wire coloring (wiring diagram) for my 1997 Mazda Protege LX was as follows:Car Radio Battery Constant 12v+ Wire: Blue/RedCar Radio Accessory Switched 12v+ Wire: Pink/BlackCar Radio Ground Wire: Black/YellowLeft Front Speaker Positive Wire (+): Blue/OrangeLeft Front Speaker Negative Wire (-): Violet/WhiteRight Front Speaker Positive Wire (+): White/RedRight Front Speaker Negative Wire (-): Yellow/RedLeft Rear Speaker Positive Wire (+): OrangeLeft Rear Speaker Negative Wire (-): YellowRight Rear Speaker Positive Wire (+): Green/BlackRight Rear Speaker Negative Wire (-): Green/Orange
I found the pinout at http://www.installdr.com to be extremely helpful.The wire coloring (wiring diagram) for my 1997 Mazda Protege LX was as follows:Car Radio Battery Constant 12v+ Wire: Blue/RedCar Radio Accessory Switched 12v+ Wire: Pink/BlackCar Radio Ground Wire: Black/YellowLeft Front Speaker Positive Wire (+): Blue/OrangeLeft Front Speaker Negative Wire (-): Violet/WhiteRight Front Speaker Positive Wire (+): White/RedRight Front Speaker Negative Wire (-): Yellow/RedLeft Rear Speaker Positive Wire (+): OrangeLeft Rear Speaker Negative Wire (-): YellowRight Rear Speaker Positive Wire (+): Green/BlackRight Rear Speaker Negative Wire (-): Green/Orange