Whites blend together.

[NikonDude]

I get this every time I shoot a macro pic in sunlight, and about every camera I have owned does it.

In low light, it does well, but when I shoot it bright day light, the colors blend.

 

[480sparky68 67]

Stop using auto exposure. The two shots you posted are prime examples of when your camera's meter flat-out lies to you.... when you've got a dark subject against a bright background, and a bright subject against a dark background.

Meters cannot tell the difference between the two.... they just blend it all together and says "Make this 18% gray". The result is over- or under-exposed subjects.

Learn to shoot in manual metering, and how to read histograms.

 

[KmH]

I get this every time I shoot a macro pic in sunlight, and about every camera I have owned does it.

As does virtually any other digital camera made today, even the $10,000 ones.

Your Canon Elph 100 HS has 3 light metering modes: Evaluative, Center-weighted, and Spot.

Read the camera's user's manual so you can learn the differences in how they work.

Using Auto mode forces the camera to use Evaluative light metering which just averages all the light in the scene, making the dark, shaded parts to dark, and the bright parts to bright.

For the first shot you posted the flower should have been Spot metered.

The camera doesn't work like your eye does. The camera is linear, your eye isn't.

Doing photography well is more about the knowledge and skill of the photographer, than what camera is used.