I have chosen black color for a textbox and want to use a blue color for the text but when someone clicks to write text the damn background changes to bright white. Can I get rid of that with some code? With other words, when someone clicks to write, the background shall stay black (or become another color). Please help me with a working code.
You don’t need code for that. You can do it from the editor.
Click the element.
Click the Edit icon
Design each of the states (hover, focus):
(On editorX, you should do it on the right panel.)
Thank you very much J.D. 
@J. D. is there a way to do it with code though? I stumbled across this and was curious if it was possible to do it with code.
As far as I know, you cannot style element with Velo code unless it’s in the Regular state (you can create your own element in an iframe or custom element and style it as you wish).
I recently submitted a feature request to be able to style different states (of buttons, but I guess they can do it more general for other elements as well) with Velo.