Toronto - An iconic Canadian landmark has been given a top-secret overhaul set to bring it out of the dark ages and in line with its contemporaries around the world, The Canadian Press has learned.

The usually dim CN Tower in Toronto is being outfitted with brilliant LED lights that shoot up the elevator shaft, over the "bubble," and straight to the mast. The project, set to dramatically brighten the downtown Toronto skyline, will be tested sporadically before its launch on Canada Day weekend.

In an era when Canadians are being told to conserve energy, it may seem counterintuitive to line the tallest freestanding structure in the world with thousands of toaster-sized LEDs.

But for the tower's chief operating officer, it's a no-brainer.

"What better way, seriously, than this, to honour the whole notion of Toronto and the nighttime sky in an elegant, architectural tribute to the legacy of the tower?" said Jack Robinson.

It's been about 10 years since the 553-metre CN Tower, which attracts some two million visitors each year, was last lit up on a regular basis.

Incandescent lights the size of washing machines which illuminated the tower following its construction in 1976 were expensive and inefficient to repair, Robinson said.

"Gradually, the lighting became less important. As of 10 years ago, the tower was virtually unlit," save essential lights for airlines, he said.

That put Toronto behind other cities in the world with high-profile landmarks - such as the Eiffel Tower in Paris - standing out against the night sky.

The CN Tower is playing catch-up because it has been waiting for the right technology, Robinson said, pointing to the new energy-saving, computer-programmed LEDs.

The new lights will use 10 per cent less energy that the current lighting, and 60 per cent less than when the tower was last fully lit in the 1990s, staff say.

The lights, which can produce millions of colours, will also be arranged to coincide with local and national events.

That means red and white lighting on Canada Day; red, white, and blue on American Independence Day; red on Valentine's Day; and maybe a hearty green on St. Patrick's Day.

Tower officials will provide a monthly guide to the lighting program, which may remind residents of the days in the 1970s when the schedule for parts of the tower's construction was published in local newspapers for the benefit of gawkers.

But people need not fear a commercial takeover or the sight of a giant corporate logo in the tower's new lights, Robinson said.

"The broad category is non-commercial. We want to make sure it's lit for appropriate reasons."

The final decisions have yet to be made, but Robinson said the lights likely won't stay on all night long.

During certain times, such as when millions of birds pass through the Toronto area during spring and fall migration, the lights will be kept off altogether.

The Fatal Light Awareness Program, a volunteer group that rescues injured birds, estimates between one million and nine million birds each year have fatal encounters with reflective or brightly lit buildings in the area.

Some birds are drawn to beaming city lights at night, and circle until they drop from exhaustion.

Robinson said the volunteer group was consulted in planning the tower's new lights.

"We're not about to decimate the bird population," he joked.

The launch party for the new lights will be held June 28 at Toronto's Roundhouse Park.

"It will be a beacon for tourism, a beacon for the city," Robinson said.