If you've noticed that sometimes your super vibrant, edited photos on desktop can look a bit less spectacular on Instagram, you aren't alone.
Over the last few years, we've seen greater adoption of devices that support a wider colour space (or palette, set of colours etc), which effectively allows the presentation of more vibrant colours, especially reds, oranges and purples. It's a subtle but noticeable improvement over the widely accepted sRGB colour space.
At present, Sked doesn't support files that utilise P3 colour. In fact, lot's of services don't support it; Slack app on desktop, Facebook in browser doesn't, but the Facebook iOS app does. It's a mixed bag of support even within a platform. Your desktop screen probably doesn't support full P3, unless you're on a fancy one designed for creative professionals.
Uploading an image that uses a P3 colour space or embedded colour profile to Instagram through Sked will result in a slightly less vibrant version being displayed. It's not always noticeable to the average user, but if you're using images with saturated reds, it won't display quite the same way.
The solution is to use the sRGB colour space, which should be your go to when you need maximum compatibility. You'll retain most of your vibrant colours, and it will look great on all devices. Here's an example of the difference when uploaded to Instagram through Sked. Image on the left used an embedded P3 colour profile, the right uses sRGB.
If you're saving from Lightroom or Photoshop, export your files using the "save for web" or a web friendly format. You can view the colour space of a file by right click > view info (MacOS) and look for Colour Profile.
In summary, the web and devices have good and improving DCI-P3 adoption, but using sRGB has the best support and is your go to for ensuring your content looks great on all devices.
A note on embedded colour profiles
When exporting from software like Lightroom, you can have an image that uses an sRGB colour space, with an embedded P3 colour profile. Here's our help guide on saving for web to ensure you have maximum compatibility