The tallest building in the West Midlands is to be lit up each night.
Birmingham comic Jasper Carrott turned on the lights on Thursday
The BT Tower in Birmingham city centre will also act as a weather forecaster with red, green and amber lights indicating changing conditions.
BT said the illumination of the 500ft building was in response to a call from the council for more landmark buildings to be lit up at night.
Local comedian Jasper Carrott switched on the lights for the first time at 1900 GMT on Thursday.
BT said powerful floodlights at the ground level of the tower are what lights up the main column of the tower white.
The top of the tower, which houses communications satellites and aerials, changes colour depending on the weather.
Mike Speechley, chartered architect at Parsons Brinckerhoff, who devised the lighting scheme, said: "The BT tower is the prime building in the city's skyline, which was my first consideration in designing the features of the lighting.
"The lighting is exciting, with subtleties which the casual observer can appreciate, both from near and afar.
"The effect is dynamic and dramatic."
Jan Rowley, from Birmingham City Council, said: "We are pleased that BT is leading the way in helping to make Birmingham's skyline truly memorable.
"We want to encourage all tall building owners to light their buildings in an imaginative and well-designed way, as this makes a major difference to the night-time appearance of our city."