The problem you've run into is too sharp a highlight. This is totally OK, you're a beginner so you're learning. Something important is to make highlights gradual.
GW has a paint system that is really great
IMO. Here's the
link. So as you can see here, what they recommend is Macragge Blue -> Drakenhof Nightshade -> Altdorf Guard Blue -> Calgar Blue. What you've done is edge highlighting. This should usually be reserved for the sharpest highlight. What I usually do is basecoat (in your case, Macragge Blue), then shade it (Drakenhof Nightshade), and then go over again with Macragge Blue, only this time avoiding the recesses where the shade has settled. Then I'd go over that with the first Layer paint (Altdorf Guard Blue here), but only on raised detail, leaving the Macragge Blue alone elsewhere. Then do the final layer paint (Calgar Blue in your case), which should be reserved for only the sharpest details. This way, the darkest color will be in the recesses, and will get progressively lighter as you progress towards the most raised surfaces, which as just like how light performs in real life.
EDIT: One VERY important tip I almost forgot. Your paints look a bit thick. Always thin your paint down with a bit of water. This helps it flow smoothly off the brush and will help ensure you get an even coat. If your paint dries and is thin enough you can still see the basecoat below it, just apply another thin layer till you're happy. The only exceptions to this rule are dry paints, which should not be watered down (or else they wouldn't be dry), and shades, which should only be watered down with medium.
Hope this helps,
- ripjaw