Niagara Falls lit up in bright purple to commemorate the long life of ... Queen Elizabeth II.

Her Majesty turned 90 years old on Thursday, the same day the world was shocked by the sudden death of legendary Purple Rain musician Prince at age 57.

The timing sparked confusion. Many on social media assumed the lights and purple falls were for music royalty.

I want to go to Niagara Falls to see the purple tribute for prince but it's an hour away and I can't drive like that yet —@CARDl_D

How cool is this? Niagara Falls goes all purple in honor of Prince! <a href="https://twitter.com/hashtag/respect?src=hash">#respect</a> <a href="https://t.co/7tEAssjMgh">pic.twitter.com/7tEAssjMgh</a> —@kevinfaiglewrdw

I can't believe they made niagra falls purple for Prince on such short notice —@notover9000

Part of the confusion came from Americans looking over from their side of the falls.

<a href="https://twitter.com/GardenStGooners">@GardenStGooners</a> <a href="https://twitter.com/canoetravel">@canoetravel</a> <a href="https://twitter.com/NiagaraParks">@NiagaraParks</a> <a href="https://twitter.com/j3rfAFC">@j3rfAFC</a> <br>Half of this Falls touches the US side so we can call that the Prince's share. —@mr_oogy_boogy

The mistake didn't just involve Niagara Falls. The CN Tower in Toronto also glowed purple to mark the Queen's birthday.

In honour of Her Majesty's birthday, the CN Tower will be lit purple and violet tonight. <a href="https://twitter.com/hashtag/HappyBirthdayYourMajesty?src=hash">#HappyBirthdayYourMajesty</a> <a href="https://t.co/uWe4WX7IBY">pic.twitter.com/uWe4WX7IBY</a> —@norm

People didn't take long to identify the CN Tower as another tribute to Prince.

As a landmark, the CN Tower has a stronger tie to the musician than Niagara Falls, since Prince was married to a Canadian woman for a time and lived in Toronto, and had said he loved the city.

And the CN Tower is purple tonight. During the purple rain... <a href="https://twitter.com/hashtag/PrinceRIP?src=hash">#PrinceRIP</a> <a href="https://t.co/cRyF20yy7O">pic.twitter.com/cRyF20yy7O</a> —@AmyMiranda

Purple CN Tower definitely takes on new meaning tonight for a city that loved Prince <a href="https://twitter.com/hashtag/RIPPrince?src=hash">#RIPPrince</a> <a href="https://t.co/wOZyIvAAz3">pic.twitter.com/wOZyIvAAz3</a> —@rachel_is_here

Toronto grieves and pays tribute to <a href="https://twitter.com/hashtag/Prince?src=hash">#Prince</a> <a href="https://t.co/7mm1J7RhU4">pic.twitter.com/7mm1J7RhU4</a> —@DebbyLong__

Several monuments around the world did, in fact, turn purple in memory of Prince.

Los Angeles city hall as well as the Forum in Inglewood, Calif., also turned the shade.

The <a href="https://twitter.com/hashtag/LAForum?src=hash">#LAForum</a> is <a href="https://twitter.com/hashtag/Purple?src=hash">#Purple</a> tonight. <a href="https://twitter.com/hashtag/RipPrince?src=hash">#RipPrince</a> <a href="https://t.co/Lv87gdBWDi">pic.twitter.com/Lv87gdBWDi</a> —@955KLOS

In Minneapolis, where Prince was born and about 32 kilometres from where he died, the I-35 W bridge shone purple at night.

Love the fact purple reigns on this Minneapolis bridge in honour of <a href="https://twitter.com/hashtag/prince?src=hash">#prince</a> <a href="https://twitter.com/hashtag/RIP?src=hash">#RIP</a> <a href="https://twitter.com/hashtag/MinnesotaDptTransport?src=hash">#MinnesotaDptTransport</a> <a href="https://t.co/MlZyVqMpSc">pic.twitter.com/MlZyVqMpSc</a> —@circlesDubai

For Canada's unintentional tributes, some are choosing not to make the connection to the Queen.

CN Tower was lit purple for the Queen's 90th Bday but we were all thinking about Prince. - <a href="https://twitter.com/PeterKash">@PeterKash</a> 📸: <a href="https://twitter.com/jamaalism">@jamaalism</a> <a href="https://t.co/tbxWG9Dztc">pic.twitter.com/tbxWG9Dztc</a> —@935TheMoveTO

I got y'all fam. Fixed it for you. <a href="https://twitter.com/canoetravel">@canoetravel</a> <a href="https://twitter.com/NiagaraParks">@NiagaraParks</a> <a href="https://t.co/ztqrjxT5QI">pic.twitter.com/ztqrjxT5QI</a> —@VonKnight

Many saw it as a fitting tribute to both figures.

The CN Tower was to be lit tonight in purple to honour the Queen's birthday. Now it will have even a more poignant meaning. <a href="https://twitter.com/hashtag/Prince?src=hash">#Prince</a> <a href="https://twitter.com/hashtag/Toronto?src=hash">#Toronto</a> —@mackaytaggart

But who knows, maybe it was intended to be this way.