doubts about colors and other things

Hi @dactou,

I hope you are well today and thank you for your questions.

1) The lines are so transparents, how can I increase the border or change the color in style.css?; I can’t find.

You can try achieving this by adding the following CSS code in the Custom CSS option of the latest version of Sparkling theme on the below path.

Admin Area -> Appearance -> Customize -> Sparkling Options -> Other -> Custom CSS

aside.widget ul li {
    border-bottom: 2px solid #BF5C5C;
}

Please change the border size and color value in the above code to whatever you want to use by referring the following pages.

http://www.w3schools.com/html/html_colorvalues.asp
http://www.w3schools.com/tags/ref_colorpicker.asp

2)How can I change the color of the buttons of tags below a post?; i can’t find in style.css.

You can change the color of the buttons of tags below a post by using the following CSS code as described above.

div.tagcloud a {
    background-color: #adbbc6;
    color: #555 !important;
}

Change color value in the above code to whatever you want to use.

3) Can I remove this text: “Theme by Colorlib Powered by WordPress” in the footer?

Yes you can remove that text by using the attached child theme of Sparkling theme on the following thread.

https://colorlibsupport.com/t/some-trouble-with-this-new-update/#post-42588

Best Regards,
Movin