Category colors

Subcategories don’t show colors into calendar table.
So I have add transparency option to category’s definition.

File: em-category.php

var $transparent;
...
...
function is_transparent_bg(){
		if( empty($this->transparent) ){
			global $wpdb;
                        $transparent = $wpdb->get_var('SELECT meta_value FROM '.EM_META_TABLE." WHERE object_id='{$this->term_id}' AND meta_key='category_transparent_bgcolor' LIMIT 1");
			$this->transparent = ($transparent == 'on');
		}
		return $this->transparent;
	}

File: em-categories-taxonomy.php

function form($tag){
                $category_transparent_bgcolor = false;
		$category_color = '#FFFFFF';
		$category_image = '';
		if( $tag != EM_TAXONOMY_CATEGORY ){ //not an add new tag form
			$EM_Category = new EM_Category($tag);
			$category_color = $EM_Category->get_color();
			$category_image = $EM_Category->get_image_url();
			$category_image_id = $EM_Category->get_image_id();
                        $category_transparent_bgcolor = $EM_Category->is_transparent_bg();
		}
		?>
	    <tr class="form-field">
	        <th scope="row" valign="top"><label for="category-bgcolor">Calendar Color</label></th>
	        <td>
                    <br/>
                    <input type="checkbox" id="category_transparent_bgcolor" name="category_transparent_bgcolor" <?php echo $category_transparent_bgcolor ? 'checked="checked"':''; ?>/> Check to set transparent background color.
                    <br/><br/>
	            <input type="text" name="category_bgcolor" id="category-bgcolor" class="colorwell" value="<?php echo esc_attr($category_color); ?>" style="width:100px;"/><br />
	            <p class="description"><?php echo sprintf(__('Choose a color for your category. You can access this using the %s placeholder.','dbem'),'<code>#_CATEGORYCOLOR</code>'); ?></p>
	            <div id="picker" style="position:absolute; display:none; background:#DEDEDE"></div>
	        </td>
	    </tr>
	    <tr class="form-field">
	        <th scope="row" valign="top"><label for="category-image">Image</label></th>
	        <td>
	        	<?php if( !empty($category_image) ): ?>
	        	<p><img src="<?php echo $category_image; ?>" /></p>
	        	<?php endif; ?>
	            <input type="text" name="category_image" id="category-image" value="<?php echo esc_attr($category_image); ?>" style="width:300px;" />
	            <input type="hidden" name="category_image_id" id="category-image-id" value="<?php echo esc_attr($category_image); ?>" />
	            <input id="upload_image_button" type="button" value="<?php _e('Choose/Upload Image','dbem'); ?>" class="button-secondary" style="width:auto;" /><br />
	            <p class="description"><?php echo sprintf(__('Choose an image for your category, which can be displayed using the %s placeholder.','dbem'),'<code>#_CATEGORYIMAGE</code>'); ?></p>
	        </td>
	    </tr>
	    <?php
	}

...
...

function save($term_id, $tt_id){
		global $wpdb;
	    if (!$term_id) return;
                if( !empty($_POST['category_transparent_bgcolor']) ){
                        $prev_settings = $wpdb->get_results('SELECT meta_value FROM '.EM_META_TABLE." WHERE object_id='{$term_id}' AND meta_key='category_transparent_bgcolor'");
			if( count($prev_settings) > 0 ){
				$wpdb->update(EM_META_TABLE, array('object_id'=>$term_id,'meta_value'=>$_POST['category_transparent_bgcolor']), array('object_id'=>$term_id,'meta_key'=>'category_transparent_bgcolor'));
			}else{
				$wpdb->insert(EM_META_TABLE, array('object_id'=>$term_id,'meta_key'=>'category_transparent_bgcolor','meta_value'=>$_POST['category_transparent_bgcolor']));
			}
                }
...
...
}

You can test effects modifying

File: templates/templates/calendar-small.php

<table class="em-calendar">
	<thead>
		<tr>
			<td><a class="em-calnav em-calnav-prev" href="<?php echo $calendar['links']['previous_url']; ?>" rel="nofollow"><<</a></td>
			<td class="month_name" colspan="5"><?php echo ucfirst(date_i18n(get_option('dbem_small_calendar_month_format'), $calendar['month_start'])); ?></td>
			<td><a class="em-calnav em-calnav-next" href="<?php echo $calendar['links']['next_url']; ?>" rel="nofollow">>></a></td>
		</tr>
	</thead>
	<tbody>
		<tr class="days-names">
			<td><?php echo implode('</td><td>',$calendar['row_headers']); ?></td>
		</tr>
		<tr>
			<?php
			$cal_count = count($calendar['cells']);
			$col_count = $count = 1; //this counts collumns in the $calendar_array['cells'] array
			$col_max = count($calendar['row_headers']); //each time this collumn number is reached, we create a new collumn, the number of cells should divide evenly by the number of row_headers
			foreach($calendar['cells'] as $date => $cell_data ){
				$eventful = ( !empty($cell_data['events']) && count($cell_data['events']) > 0 );
				$class = ( !empty($cell_data['events']) && count($cell_data['events']) > 0 ) ? 'eventful':'eventless';
				if(!empty($cell_data['type'])){
					$class .= "-".$cell_data['type'];
				}
				?>
				<!-- <?php print_r($cell_data); ?>-->
				<td class="<?php echo $class; ?>" style="background-color:<?php
						if ( ! empty($cell_data['events']) ){
							foreach( $cell_data['events'] as $EM_Event ){
                                                            try{
                                                                $categories = $EM_Event->get_categories()->categories;
                                                                foreach( $categories as $category){
                                                                    if( $category->is_transparent_bg()==false && $category->get_color()!='#FFFFFF' ) echo $category->get_color();
                                                                }
                                                            } catch (Exception $e){
                                                                echo '<!--Caught exception: ',  $e->getMessage(), "-->\n";
                                                            }
							}
						}
					?>;">
					<?php if( !empty($cell_data['events']) && count($cell_data['events']) > 0 ): ?>
					<a href="<?php echo esc_url($cell_data['link']); ?>" title="<?php echo esc_attr($cell_data['link_title']); ?>"><?php echo date('j',$cell_data['date']); ?></a>
					<?php else:?>
					<?php echo date('j',$cell_data['date']); ?>
					<?php endif; ?>
				</td>
				<?php
				//create a new row once we reach the end of a table collumn
				$col_count= ($col_count == $col_max ) ? 1 : $col_count+1;
				echo ($col_count == 1 && $count < $cal_count) ? '</tr><tr>':'';
				$count ++;
			}
			?>
		</tr>
	</tbody>
</table>

http://wordpress.org/extend/plugins/events-manager/