in_category condition not working

How is it not working for you? The code shows the special text for any posts that have the category green and/or oolong assigned. Is this not what you want?

This code is on a template inside the Loop, yes? A link to a page demonstrating the problem might help.

Thanks for your reply bcworkz. It is not working in the sense that the Category “Green” or “Oolong” is only displaying “Quantity” rather than the label with the weight. Here is the complete page code below. Maybe there is an issue with my syntax that I am missing. Thank for any assistance! ??

<?php

global $woocommerce, $product;

if ( ! $product->is_purchasable() ) return;
?>

<?php
	// Availability
	$availability = $product->get_availability();

	if ($availability['availability']) :
		echo apply_filters( 'woocommerce_stock_html', '<p class="stock '.$availability['class'].'">'.$availability['availability'].'</p>', $availability['availability'] );
    endif;
?>

<?php if ( $product->is_in_stock() && is_shop_enabled() ) : ?>

	<?php do_action('woocommerce_before_add_to_cart_form'); ?>

	<form action="<?php echo esc_url( $product->add_to_cart_url() ); ?>" class="cart" method="post" enctype='multipart/form-data'>

	 	<?php do_action('woocommerce_before_add_to_cart_button'); ?>

	 	<?php if ( ! $product->is_sold_individually() ){   ?>            

                <label> <?php if ( in_category('Green') ) { ?>

    <label><?php _e( 'Quantity - 150 G', 'yit' ) ?></label>

<?php } elseif ( in_category('Oolong') ) { ?>

    <label><?php _e( 'Quantity - 150 G', 'yit' ) ?></label>

<?php } else { ?>

<label><?php _e( 'Quantity', 'yit' ) ?></label>

<?php } ?></label>

				<?php
	 			woocommerce_quantity_input( array(
	 				'min_value' => apply_filters( 'woocommerce_quantity_input_min', 1, $product ),
	 				'max_value' => apply_filters( 'woocommerce_quantity_input_max', $product->backorders_allowed() ? '' : $product->get_stock_quantity(), $product )
	 			) );
			}
	 	?>

	 	<button type="submit" class="single_add_to_cart_button button alt"><?php echo apply_filters('single_add_to_cart_text', __( 'Add to cart', 'yit' ), $product->product_type); ?></button>

	 	<?php do_action('woocommerce_after_add_to_cart_button'); ?>

	</form>

	<?php do_action('woocommerce_after_add_to_cart_form'); ?>

<?php endif; ?>

This code does not appear to be within a standard WP “Loop”. in_category() either needs the post ID as a parameter or it needs to be within the Loop where the global $post is available.

I’m guessing $product is the current object for this code. If this object has an ID to which categories are attached, pass it as the second parameter and then your code will work correctly.

Still not having much luck with this. This is now showing “Quantity 150” for all simple products. hmmm….

<?php
global $woocommerce, $product;

if ( ! $product->is_purchasable() ) return;
?>

<?php
	// Availability
	$availability = $product->get_availability();

	if ($availability['availability']) :
		echo apply_filters( 'woocommerce_stock_html', '<p class="stock '.$availability['class'].'">'.$availability['availability'].'</p>', $availability['availability'] );
    endif;
?>

<?php if ( $product->is_in_stock() && is_shop_enabled() ) : ?>

	<?php do_action('woocommerce_before_add_to_cart_form'); ?>

	<form action="<?php echo esc_url( $product->add_to_cart_url() ); ?>" class="cart" method="post" enctype='multipart/form-data'>

	 	<?php do_action('woocommerce_before_add_to_cart_button'); ?>

	 	<?php if ( ! $product->is_sold_individually() ){   ?>
          <?php  if ( in_category( 'Green', $product->id ) || in_category( 'Oolong', $product->id ) || in_category( 'White', $product->id )) {?>
                <label><?php _e( 'Quantity 150 G', 'yit' ) ?></label>
          <?php }else {?>
                <label><?php _e( 'Quantity', 'yit' ) ?></label>
          <?php }?>

				<?php
	 			woocommerce_quantity_input( array(
	 				'min_value' => apply_filters( 'woocommerce_quantity_input_min', 1, $product ),
	 				'max_value' => apply_filters( 'woocommerce_quantity_input_max', $product->backorders_allowed() ? '' : $product->get_stock_quantity(), $product )
	 			) );
			}
	 	?>

	 	<button type="submit" class="single_add_to_cart_button button alt"><?php echo apply_filters('single_add_to_cart_text', __( 'Add to cart', 'yit' ), $product->product_type); ?></button>

	 	<?php do_action('woocommerce_after_add_to_cart_button'); ?>

	</form>

	<?php do_action('woocommerce_after_add_to_cart_form'); ?>

<?php endif; ?>

My lack of knowledge of your commerce system is showing. $product must be a custom post type or something. in_category() only works for ‘post’ post types. For other objects, you need to use a more generic function. Try this:
is_object_in_term( $product->id, 'category', array( 'Green', 'Oolong', 'White',))

Note how you can place all terms (to match any of) in an array, avoiding a clumsy OR logic sequence. I hope this works as this is the best I can offer considering my lack of knowledge of your commerce system. If it still does not work, it is due to some small data mismatch or typo, as this function should work on any object (in theory).