>>>>>. I already changed the color into black under properties section but its not working, still in yellow color and others in red and green.
In the dimension style you are using for creating these dimensions, all lines have color property assigned to "Yellow":
And text color to "Green":
If you want them to have the color of current Layer, or you want to change their color with Color property in the Properties Inspector, you need to set their color property to "ByBlock":
I hope you know how to modify existing Dimension style:
If you don't want to modify dimension style, you can change color of line elements in each dimension with Properties Inspector: select dimension and change color in "Lines & Arrows" and "Text" sections of Properties Inspector:
