My styles.less for my Atom editor. Uses Spacegray Dark for the UI and syntax theme.

styles.less

/*
 * Your Stylesheet
 *
 * This stylesheet is loaded when Atom starts up and is reloaded automatically
 * when it is changed.
 *
 * If you are unfamiliar with LESS, you can read more about it here:
 * http://www.lesscss.org
 */

.tree-view {
	background: rgb(32, 36, 45);
	font-size: 1.0rem;
}

.editor {
	background: rgb(32, 36, 45);
}

.editor .cursor {
	color: rgb(214, 128, 172);
}

.editor .gutter {
	background: rgb(32, 36, 45);
}

.status-bar {
	background: rgb(32, 36, 45);
}

.tab-bar {
	background: rgb(32, 36, 45);
}

.tab {
	background: rgb(32, 36, 45);
}

.tab .title {
	color: rgb(207, 124, 71);
}

.tab-bar .tab.active, .tab-bar .tab.active:before {
	background: rgb(32, 36, 45);
}
.close-icon {
	color: rgb(207, 124, 71);
}