Hi
In the Blog entries stack, for Summary Colors, it’s not possible at all to use the transparency setting for any of item colors, just a straight color is supported 
On the opposite, for Full entry Colors, transparency setting is OK for any the items that can be colorized 
Strange ?
Is it strange? No, that is simply how it was coded. I didn’t see a huge need for opacity sliders for Summary or Full Entries. That said I added them to Full Entries at the request of users, but missed adding them for the Summary View.
The next version will have opacity slider enabled for these items.
Excellent ! Thanks Adam
This is a need for me
Could you sate my curiosity and give me the use case so I can understand how it is being used and the reason transparency in particular is needed?
Yes I have a background looping video (of nature) all my site is displayed onto that background. Si transparence is highly used eveywhere including in blog post summary(but transparrency is not working with Alloy) and in blog post détail (here Alloy transparence is Ok).
So transparency consistency is needed in both blog post summary and blog post détails I think